Devices and methods for high precision fluid injection

Abstract

Devices are described for injecting medicant, gel, treatment fluid or a substance into a target region in a target object. The devices include a housing with a main body and distal end portion; a moveable needle at a distal end portion and having a needle tip with a needle bore opening for injection into the target region; an actuation assembly for deploying the needle along a needle insertion trajectory to the target region; and a dispensing assembly for moving the medicant, treatment fluid or substance to the needle tip. The needle and / or device is adapted to reduce backflow of the medicant, gel, treatment fluid or substance during injection by having (a) a needle shape for the needle tip and / or a needle shaft, and / or (b)the needle insertion trajectory that are adapted to place substantially all of the needle bore opening in the target region and reduce gaps between the needle and surrounding portions of the target object.

Description

TITLE: DEVICES AND METHODS FOR HIGH PRECISION FLUID INJECTIONRELATED APPLICATION

[0001] This application claims benefit of United States provisional patent application serial no. 63 / 726,099 filed November 27, 2024, incorporated herein by reference in its entirety.FIELD

[0001] The various embodiments described herein generally relate to injection and drainage devices and methods with a needle, including a variable or fixed length needle, having a needle geometry to reduce leakage or backflow, used for precise, accurate, and controlled delivery and / or drainage of medicants, fluids, or other substances to or from targeted locations including, but not limited to, various ocular sites such as the suprachoroidal, subretinal, and supraciliary spaces and other ocular locations, for example, as well as any other narrow, thin, or small space or tissue elsewhere in the body.BACKGROUND

[0002] The following paragraphs are provided by way of background to the present disclosure. They are not however an admission that anything discussed therein is prior art or part of the knowledge of a person of skill in the art.

[0003] A variety of devices and methods exist for delivering fluid or medicant to different regions of the eye via different routes during treatment of a condition. The most common among these are topical, subconjunctival, intravitreal, and subretinal routes. For many applications, these treatments are either non-localized, exposing healthy tissue to the drug and / or not suitable for certain diseases as the drug does not reach the target tissue with sufficient concentration and requiring larger doses, or they are invasive, and sometimes both.

[0004] In recent years, delivery of fluid or medicant via the suprachoroidal space (SCS) has been explored as an alternative to these traditional methods of treatment for a wide range of diseases, including macular edema, age-related macular degeneration,non-infectious uveitis, hereditary retinal diseases, and glaucoma. Suprachoroidal injections have the potential for greater localization and sequestration of injected medicant while being potentially less invasive.

[0005] The SCS is a potential space between the sclera and choroid of the eye. Though the sclera and choroid are adjacent tissues, their functions and mechanical properties are vastly different. The sclera is a tough, collagenous tissue that supports and protects the eye, while the choroid is a highly vascular layer that supplies blood and nutrients to the outer retina. When a positive pressure is introduced between these two layers by injecting a fluid, the choroid pulls away from the sclera and a pocket of fluid, or “bleb”, is created. If left, this fluid may disperse circumferentially around the eye in the SCS and be absorbed by surrounding tissues, including the choroid and retina, over time. The rate of closure or reduction of the space depends on the viscosity and other properties of the injected fluid

[0001] , Agents with higher viscosity induce slower closure / reduction rates [2],

[0006] As an example of a treatment application using fluid delivered to the SCS, Suprachoroidal Viscopexy (SCV) is a minimally invasive technique recently developed for treating rhegmatogenous retinal detachment [3], The SCV technique has the potential to greatly reduce the cost and recovery time of retinal detachment repair while also improving the quality of the repair. It can be performed with no incision, no tamponade agent, and no patient post-operative positioning requirements [3], SCV works by injecting viscous fluid into the SCS, creating a “bleb” of fluid underneath the tear that pushes the choroid towards the retina and allows it to reattach. Laser retinopexy is then performed around the retinal tear to create a permanent chorioretinal adhesion. A safe and reliable device for performing the SCV technique anywhere a tear occurs may greatly change how retinal detachments are treated and improve patient outcomes. Other therapeutic fluids (e.g., pharmaceuticals, cell and gene therapies) may also be delivered to the SCS for the treatment of a variety of other conditions.

[0007] While there exists great potential for suprachoroidal delivery of medications or drugs or other agents to improve patient outcomes for many conditions, there are also risks that must be minimized in order for this technique to be widely adopted. One suchrisk is the potential for the delivered fluid to leak from the needle during injection or back out of the SCS or sclera (i.e. backflow) during or after injection through the channel in the sclera created by the delivery device. SCV is an extremely precise operation which uses small amounts of viscoelastic fluid, as are drug delivery applications that utilize small amounts of an often-expensive therapeutic fluid. Fluid leakage can therefore be costly and compromise treatment efficacy. Similar risks and challenges apply to needle-based delivery of fluids to other ocular locations as well.

[0008] Minimizing fluid leakage or backflow is a priority since the viscoelastic or other treatment fluid or drug to be delivered may often be a limited and expensive resource. Fluid leakage or backflow may also prevent the appropriate volume and concentration of viscoelastic or other treatment fluid or drug from being delivered to the SCS or other target location, reducing the effectiveness of the treatment in the targeted area. For example, in SCV excessive viscoelastic fluid backflow may prevent expansion of the suprachoroidal space preventing the intended indentation of the choroid and compromising the repair of the retinal detachment.

[0009] Traditional needle designs face these and other difficulties when injecting into thin tissue layers, between tissue layers, or other thin, narrow, or small spaces, particularly in allowing low needle insertion forces and ensuring precise placement but also minimizing or preventing fluid backflow and leakage. Accordingly, there is a need for a device that can be used to perform suprachoroidal, subretinal, supraciliary, and other delivery, including SCV, with a needle structure that limits fluid backflow or leakage during operation, while also reducing a likelihood of overpenetration.SUMMARY OF VARIOUS EMBODIMENTS

[0010] Various embodiments are described herein of devices and related methods for the injection and drainage of fluids, including devices and methods with a variable length needle that can be extended and / or retracted for precise, accurate, and controlled delivery and / or drainage of medicants, fluids, or other substances to or from targeted locations including, but not limited to, ocular sites including the suprachoroidal, subretinal, and supraciliary spaces. This may involve precisely advancing an adjustable length orfixed length needle with enough resolution and sensing to locate potential spaces, cavities, and thin tissues within the body, such as the SCS and the subretinal space in the eye, for example. At least some of the devices and methods described herein may also apply to straight or curved needle injections with traditional needles or microneedles.

[0011] In one aspect, in accordance with the teachings herein, there is provided at least one embodiment of a device for injecting medicant, gel, treatment fluid or a substance into a target region in a target object, wherein the device comprises: a housing defining a main body and a distal end portion; a needle at a distal end portion of the main body of the device, the needle having a needle tip with a needle bore opening for injection into the target region, and the needle being moveable; an actuation assembly for deploying the needle so that the needle tip follows a needle insertion trajectory to the target region; and a dispensing assembly for moving the medicant, treatment fluid or substance to the needle tip during injection, wherein the needle and / or device is adapted to reduce backflow or leakage of the medicant, gel, treatment fluid or substance during delivery by having: (a) a needle shape for the needle tip and / or needle shaft; and / or (b) the needle insertion trajectory that are adapted to place substantially all of the needle bore opening in the target region and reduce gaps between the needle and surrounding portion of the target object through which the needle is inserted.

[0012] In at least one embodiment, the device further comprising an ampoule containing the medicant, gel, treatment fluid or substance, the needle being coupled to the ampoule via a needle conduit; and a dispensing assembly for moving the medicant, treatment fluid or substance from the ampoule to the needle tip during injection.

[0013] In at least one embodiment, the device further comprises a needle holding member that is disposed within the housing and the needle is located at a distal portion of the needle holding member, wherein the actuation assembly is adapted to move the needle holding member to extend the needle from within the housing to outside of the housing during needle deployment.

[0014] In at least one embodiment, the needle holding member has a pivot point and is pivotable to cause the needle to follow a curved insertion trajectory during insertion tothe target region, and wherein a distance from the pivot point to the needle tip defines a radius for an arc of the curved insertion trajectory.

[0015] In at least one embodiment, the distance between the pivot point of the needle holding member and the needle tip is selected to predefine the curved insertion trajectory to cause the needle tip to enter the target region to within + / - 30 degrees of a normal of the surface of the target region.

[0016] In at least one embodiment, the needle shaft has a curved shape with a radius of curvature that approximately matches the radius of curvature of the curved needle insertion trajectory.

[0017] In at least one embodiment, the needle bevel has a curved surface.

[0018] In at least one embodiment, the needle tip has a needle bevel with at least one bevel segment having a curved bevel.

[0019] In at least one embodiment, the at least one needle bevel segment is circular or is a polynomial curve.

[0020] In at least one embodiment, the needle tip has a needle bevel with at least one bevel segment having one or more straight bevel cuts.

[0021] In at least one embodiment, the needle bevel has one or more surfaces having bevel cuts which may be continuous or discrete.

[0022] In at least one embodiment, the needle bevel or the one or more straight bevel segments form an angle between about 10 and about 60 degrees, or about 10 degrees to about 45 degrees, or about 25 to about 30 degrees.

[0023] In at least one embodiment, the needle bevel has two or more segments including a distal segment with a first angle or first curve for a desired sharpness of the needle tip and a proximal segment having a second angle or second curve that is greater than the first angle to reduce the length of the needle bore opening.

[0024] In at least one embodiment, the needle has a tapered needle shaft and may transition from a larger diameter to a smaller diameter, vice versa or in some other fashion, for stretching portions of the target object that are adjacent to the needle shaftwhen the needle is inserted into the target region thereby improving sealing around the needle shaft at the adjacent portions of the target object.

[0025] In at least one embodiment, the taper has a linear, curved, or irregular profile in one or more steps along one or more portions of the needle shaft.

[0026] In at least one embodiment, the taper includes a notched portion, a bumped portion, or a flanged portion.

[0027] In at least one embodiment, the needle is located at a lateral surface of the distal end portion of the main body of the device where the lateral surface is used to contact the surface of the target object.

[0028] In at least one embodiment, the target object is convex and the lateral surface has a concave shape to distribute applied pressure to a surface of the target object during needle insertion.

[0029] In at least one embodiment, the device comprises an indenter that protrudes from a the distal end portion of the device so that the indenter surrounds an exit location of the needle to form a seal around a needle entry point at a surface of the target object when the needle is deployed.

[0030] In at least one embodiment, the indenter is adapted to locally stretch (e.g., preload) the surface of the target object when the instrument tip is pressed against the exterior of the target object to reduce local deflection of the surface of the target object as the needle penetrates the target object, thereby reducing the “tenting” effect and resultant sudden uncontrolled “punch through”.

[0031] In at least one embodiment, the indenter is shaped as a boss, a mesa, or a rounded post.

[0032] In at least one embodiment, the indenter is made of a resilient compressible material.

[0033] In at least one embodiment, the needle is deployed from a lateral surface of the distal end portion of the main body of the device or the needle is deployed from an endface of a distal end portion of the device where the end face is intersected by a longitudinal axis of the distal end portion of the device.

[0034] In at least one embodiment, the ampoule has multiple chambers with a distal chamber including a displacement fluid and a proximal chamber including the medicant, the gel, the treatment fluid or the substance.

[0035] In at least one embodiment, the dispensing assembly includes a plunger that when actuated causes deployment of the displacement fluid through the needle bore followed by deployment of the medicant, the gel, the treatment fluid or the substance through the needle bore.

[0036] In at least one embodiment, the ampoule is compressible by the plunger, or the plunger is adapted to enter into a proximal end of the ampoule during deployment of the displacement fluid, followed by deployment of the medicant, the gel, the treatment fluid or the substance.

[0037] In at least one embodiment, the displacement fluid is air, CO2, SF6, c3F8 or a liquid.

[0038] In at least one embodiment, the target object is an eye.

[0039] In at least one embodiment, the target region is a suprachoroidal space, a subretinal space, or a supraciliary space.

[0040] In another aspect, in accordance with the teachings herein, there is provided a method for injecting medicant, gel, treatment fluid or a substance into a target region in a target object using a device that is defined according to any one of the embodiments described herein, wherein the method comprises: inserting a needle having a needle bore opening into the target object so that the needle bore is contained within the target region; and dispensing the medicant, gel, treatment fluid or a substance into the target region.

[0041] In at least one embodiment, the needle is deployed so that the needle tip follows a curved insertion trajectory to the target region, and wherein a distance from a pivot point to the needle tip defines a radius for an arc of the curved insertion trajectory.

[0042] In at least one embodiment, the needle is deployed so that the needle tip follows a curved insertion trajectory to the target region that is defined to cause the needle tip to enter the target region to within + / - 30 degrees of a normal of the surface of the target region.

[0043] In at least one embodiment, the method includes deploying a displacement fluid into the target region before deploying the medicant, gel, treatment fluid or a substance into the target region.

[0044] It will be appreciated that the foregoing summary sets out representative aspects of embodiments to assist skilled readers in understanding the following detailed description. Other features and advantages of the present application will become apparent from the following detailed description taken together with the accompanying drawings. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments of the application, are given by way of illustration only, since various changes and modifications within the spirit and scope of the application will become apparent to those skilled in the art from this detailed description.BRIEF DESCRIPTION OF THE DRAWINGS

[0045] For a better understanding of the various embodiments described herein, and to show more clearly how these various embodiments may be carried into effect, reference will be made, by way of example, to the accompanying drawings which show at least one example embodiment, and which are now described. The drawings are not intended to limit the scope of the teachings described herein.

[0046] FIG. 1 is a section view of the human eye with a retinal detachment and an embodiment of a device with a tip having a needle that is extended to protrude into the scs.

[0047] FIG. 2 shows part of the SCV procedure where viscous fluid has been injected into the SCS to create a bleb.

[0048] FIG. 3 illustrates how traditional straight needles cannot reach posterior regions of the eye with a straight entry.

[0049] FIG. 4 depicts how a physician might hold one embodiment of a device that is in accordance with the teachings herein for reaching a region of the eye that is not easily accessible with conventional devices.

[0050] FIGS. 5A-5E show example embodiments of devices having needle bevels with different geometries where the embodiments of FIGS. 5A-5C and 5E are in accordance with the teachings herein to prevent fluid backflow.

[0051] FIGS. 6A-6B show example embodiments of needles with a tapered needle shaft.

[0052] FIGS. 7A-7C show perspective, front and side views, respectively, of an example embodiment of a device with an indenter on the distal end of the device.

[0053] FIG. 8A illustrates an example of tissue stretching when a straight needle is inserted into the eye along a curved path defined by the pivoting action of a lever.

[0054] FIG. 8B illustrates an example embodiment of a deployment guide for use at the distal end portion of the main body of the device for constraining the direction of the needle exit from the device during deployment.

[0055] FIG. 8C illustrates how a needle assembly may be deployed such that the plane of the needle bevel is less perpendicular and more tangent to the eye when the needle trajectory is curved.

[0056] FIG. 9A-9C show an example embodiment of a device having a needle actuation assembly that causes the needle to follow a curved path when the needle is advanced / extended.

[0057] FIG. 9D shows an example of adapting an actuation assembly having a cantilever beam to function as a pivoting actuation assembly, where as the beam is deflected the deflection and slope of the end of the cantilever beam create a curved path for a needle located at the end of the beam to penetrate the eye.

[0058] FIGS. 10A-10C show an example embodiment of a device that uses an ampoule I cartridge having multiple distinct fluids where in a first position (FIG. 10B) one of the fluids can be automatically dispensed / pushed into a target region through a needleand in a second position another different fluid can be dispensed / pushed into the target region through the needle.

[0059] Further aspects and features of the example embodiments described herein will appear from the following description taken together with the accompanying drawings.DETAILED DESCRIPTION OF THE EMBODIMENTS

[0060] The headings and Abstract of the Disclosure provided herein are for convenience only and do not interpret the scope or meaning of the embodiments.

[0061] Various embodiments in accordance with the teachings herein will be described below to provide examples of at least one embodiment of the claimed subject matter. No embodiment described herein limits any claimed subject matter. The claimed subject matter is not limited to devices, systems or methods having all of the features of any one of the devices, systems or methods described below or to features common to multiple or all of the devices, systems or methods described herein. It is possible that there may be a device, system or method described herein that is not an embodiment of any claimed subject matter. Any subject matter that is described herein that is not claimed in this document may be the subject matter of another protective instrument, for example, a continuing patent application, and the applicants, inventors or owners do not intend to abandon, disclaim or dedicate to the public any such subject matter by its disclosure in this document.

[0062] Furthermore, it will be appreciated that for simplicity and clarity of illustration, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements or steps. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein may be practiced without these specific details. In other instances, well-known methods, procedures and components have not been described in detail so as not to obscure the embodiments described herein. Also, the description is not to be considered as limiting the scope of the embodiments described herein.

[0063] It should also be noted that the terms “coupled” or “coupling” as used herein can have several different meanings depending on the context in which these terms are used. For example, the terms coupled or coupling can have a mechanical or fluidic connotation. For example, as used herein, the terms coupled or coupling can indicate that two elements or devices can be directly connected to one another or connected to one another through one or more intermediate elements or devices via a mechanical or fluidic element depending on the particular context.

[0064] Unless the context requires otherwise, throughout the specification and claims which follow, the word “comprise” and variations thereof, such as, “comprises” and “comprising” are to be construed in an open, inclusive sense, that is, as “including, but not limited to”.

[0065] It should also be noted that, as used herein, the wording “and / or” is intended to represent an inclusive-or. That is, “X and / or Y” is intended to mean X or Y or both X and Y, for example. As a further example, the phrases “X, Y, and / or Z”, “any operable combination of X, Y and Z”, “X, Y, Z or any combination thereof” or “any combination of X, Y and Z” is intended to mean X, Y, Z, X and Y, X and Z, Y and Z, or X, Y and Z.

[0066] It should be noted that terms of degree such as “substantially”, “about” and “approximately” as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. These terms of degree may also be construed as including a deviation of the modified term, such as by 1 %, 2%, 5%, 10% or 15%, for example, if this deviation does not negate the meaning of the term it modifies.

[0067] Furthermore, the recitation of numerical ranges by endpoints herein includes all numbers and fractions subsumed within that range (e.g., 1 to 5 includes 1 , 1.5, 2, 2.75, 3, 3.90, 4, and 5). It is also to be understood that all numbers and fractions thereof are presumed to be modified by the term “about” which means a variation of up to a certain amount of the number to which reference is being made if the end result is not significantly changed, such as 1 %, 2%, 5%, 10% or 15%, for example.

[0068] It should be noted that as used herein terms such as proximal and distal of a device or component in the device are defined with respect to the operator (e.g., human or robotic) contact point of the devices described herein. Accordingly, an upper portion of a handle of the device is referred to as a proximal portion of the device while an end portion of the device with a needle that is inserted into a physiological structure is a distal portion of the device.

[0069] In addition, it should be noted that the term distal end portion of a device is meant to cover a region at a distal end of the device and is not limited to the very distal tip of the device. Accordingly, components that are located at the distal end portion of a device does not mean that those components are limited to being located at the very distal tip of the device.

[0070] It should be understood that the needle bevels described herein generally have a curved surface which may be referred as a “bevel curve” or “needle bevels”.

[0071] It should be understood that a target object referred to herein may be a physiological or biological organ or tissue of a human or animal and that a target region of the target object in such cases can be a particular tissue layer or other location within the target object. In the examples which follow the eye is the target object that is primarily discussed but it should be understood that the devices described herein may be used with other types of target objects. When the target object is the eye the target object has a convex surface that is to be penetrated by the needle of the device.

[0072] It should be understood that when the needle is being described as being deployed, extended from within the housing of the device, extended outside of the housing of the device, or following an insertion trajectory or similar phrasings that the term “needle” in these contexts means the needle tip and a portion of the needle shaft that is adjacent the needle tip.

[0073] As described previously, while there exists great potential for SCV to improve retinal detachment repair, and for therapeutic fluids in the SCS or subretinal space to improve treatment of other ocular conditions, there are also risks that must be minimizedin order for it to be widely adopted. For example, as discussed herein, uncontrolled fluid leakage or backflow can incur costs and undermine therapeutic outcomes.

[0074] Preventing fluid leakage or backflow during SCV or other fluid injection procedures is challenging for various reasons. For example, the inventors have realized that if the opening at the tip of the injection device needle is placed only partially in the SCS and partially in the sclera or partially outside of the eye entirely, when fluid is injected some of it will enter the SCS and some of it may flow to the outside of the eye. If the resistance to fluid flow is lower at portions of the opening outside the SCS than at portions of the opening in the SCS, the injected fluids may flow substantially through this lower resistance path and leak or backflow out of the eye. This is especially problematic when the needle is shaped with a bevel at a shallow angle, which makes the needle sharp for easier penetration of the sclera but also makes the needle opening long (e.g., the largest dimension of the needle opening too large) such that it may be difficult or impossible to place the entire needle opening in the SCS. However, if the needle tip is shaped with a bevel at a larger angle to make the opening shorter (have less of a vertical extent) so that a greater portion (or all) of the needle opening can be placed in the SCS, the needle sharpness will be reduced, and it may be more difficult for the needle to penetrate into the eye at all. This trade-off between needle sharpness and needle opening length (e.g., needle opening height due to angle) applies to needles used for drainage of fluids from target locations, as well as for injection of fluids.

[0075] Even when an operator is able to position the needle opening entirely within the correct space (the SCS in this example), injected fluids can have a tendency to flow out of the eye due to a number of factors. For example, fluid backflow may also occur around the needle and back through the puncture hole (i.e. , at the insertion point) while the needle is inserted, or through the puncture hole after the needle is removed. When there is an increased local pressure in the SCS (or inside a different target location where the needle tip is applied), which may be the case for ocular conditions that involve increased intraocular pressure and / or after fluids have been injected into the SCS causing a local pressure increase, there is a greater potential for increased backflow through the puncture hole.

[0076] In accordance with the teachings herein, there is provided at least one embodiment of an ocular treatment device that is configured to have a needle bevel geometry shaped to prevent or reduce fluid backflow. In general, these device embodiments include a needle tip, an actuation assembly for advancing the needle along a needle insertion path, as well as a needle shaft shape and / or a needle tip shape that is adapted for improved for fluid injection in thin tissues, in tissue spaces or between tissue layers such as, for example, the SCS, the subretinal space, the supraciliary space, the subcutaneous layers, and or other potential spaces between tissue or other small, thin, or narrow target locations. A target location, target region or target space is a region in which the needle tip of the device is inserted to perform some action such as delivering treatment fluid or draining fluid, for example.

[0077] In accordance with the teachings herein, there is provided at least one embodiment of an ocular treatment device that has an improved ability to deliver fluid accurately to the target location while reducing the risk of leakage or misdirected delivery.

[0078] The various embodiments of the ocular treatment device and associated methods of use described herein allow a physician to safely probe and manipulate tissue and then precisely extend a needle tip from the face of the device, which can be referred to as a lateral or side firing where the needle tip exits a lateral surface of an end portion of the main body of the device approximately perpendicularly where the lateral surface is placed adjacent to the ocular surface, although the teachings herein may be used in some devices that have an end firing configuration in which the needle tip may extend from the tip of the main body of the device approximately parallel with the longitudinal axis of the device. The device may be hand-held by a surgeon, for example, or attached to a moveable mechanical mount or a robotic arm for performing a procedure. Once the needle tip has advanced into the correct location within the tissue, medicant or other fluid can be dispensed from the device.

[0079] Furthermore, while the various device and needle embodiments are described herein with respect to injection of medicant, gel, treatment fluid or other substance into a target region in a target object, it should be understood that these devices and needle embodiments may also generally be used for performing drainage in a target region of atarget object such as draining fluid from a region of an organ such as from a subretinal region of the eye.

[0080] Referring now to FIG. 1 , shown therein is an example embodiment of an ocular treatment device 100 that has an extendable needle 101 at a distal end portion 102 and is configured to reliably navigate the tip of the needle 101 into a certain location, such as the suprachoroidal space (SCS) 103 between the sclera 104 and choroid 105, for example. Once the needle tip 102 is in the SCS 103, a medicant, gel, treatment fluid or a substance, such as, but not limited to an ophthalmic viscoelastic fluid (OVF), a viscoelastic for SCV, hydrogels, spheres containing medication, medications / drugs / pharmaceuticals, gene therapies, steroids, or cell-based therapies, is injected which at first creates a suprachoroidal bleb 201 that accumulates in the SCS as illustrated in FIG. 2 under an open retinal tear 107, or at any other location. The insertion of this fluid moves structures of the eye which aids in repair such as allowing the retina 106 to reattach by using the OVF to cause a choroidal indentation / buckle underneath the retina 106 thus closing the retinal tear 107. The subretinal fluid 202 is absorbed by the retinal pigment epithelium over time, allowing the rest of the retina to reattach. This process is described in United States Non-Provisional Patent Application No. 18 / 770,797 filed on July 11 , 2024, and titled “DEVICES AND METHODS FOR POSTERIOR EYE SEGMENT ACCESS WITH ACCURATE LOCALIZATION AND NEEDLE PENETRATION DEPTH”, which is hereby incorporated by reference. In other embodiments, fluid may be injected into the SCS of an eye that does not have a retinal tear or detachment, and depending on the properties of the fluid, it may either form a bleb or it may flow and distribute around the eye. In other embodiments, the needle may be advanced into the subretinal space and the fluid delivered there.

[0081] The shape of the ocular treatment device 100, and alternative embodiments thereof, is configured to be intuitive for the physician to hold as well as conducive to reaching various regions on the eye and various needle insertion depths without causing eye damage or at least reducing or minimizing any eye damage during use. Before or during injection into the eye, the operator (e.g., a physician or surgeon) may apply pressure to the injection site with a lateral surface of the distal end portion 102 of thedevice 100 that touches the ocular surface, allowing the location of the distal end potion of the device 100 to be seen from inside the eye with indirect ophthalmoscopy or a microscope. The lateral surface of the distal end potion 102 of main body of the device100 makes contact with the injection site which helps to prevent fluid leakage. While this activity is described with respect to device 100, this applies to one or more other embodiments of the devices described herein. Most retinal tears occur at the vitreous base or in some cases more posterior such as the equator of the globe and further back, making them difficult to access with conventional, straight needles, as shown in FIG. 3.

[0082] The shape / form factor of the main body 100b of the device 100, where the main body 100b is defined by an outer housing 100h, is selected to be generally similar to scleral depressors, which are a common tool in ophthalmology to indent the walls of the eye during retinal examinations. Physicians are comfortable with using devices having a form factor that is similar to that of a scleral depressor. FIG. 4 shows how a physician might indent the eye with the device 100. However, there are some differences in the form factor of the device 100 and that of a scleral depressor in that the distal end portion of the main body of the device 100, which has a lateral surface that makes contact with the outer surface of the eye during use, may have a radius of curvature that allows the lateral surface of the distal end portion of the device 100 to better conform with the surface of the globe (of the eye) to reach a desired needle insertion location. Also, the lateral surface of the distal end portion 102 of the device 100 may have a spoon-shaped region or concave shaped region disposed about the location where the needle tip is extended from the device which aids in safely distributing pressure across the globe and reaching underneath patients’ eyelids with ease. Prior to actuation of the needle 101 , the needle101 is held within the device 100 fully retracted and the lateral surface of the device 100 that makes contact with the outer surface of the eye during use is smooth. This allows the physician to probe and manipulate the eye by moving the end portion of the device 100 with the needle retracted so that the needle tip does not extend past the surface of the device to avoid scratching / injuring the eye and then extending the needle tip to deliver medicant with the same device when it is at the proper location on the globe.

[0083] The tip of the needle 101 extends perpendicularly from the lateral surface 102f of the device 100a in contact with the eye. This topology allows the physician to reach areas of the eye where a straight needle with direct entry cannot because of the ocular bones, as shown in FIG. 4. The radius of curvature of the distal end portion 102 of the device 100a matches the approximate radius of curvature of the human eye. The tip of the needle 101 may extend approximately perpendicularly, such as plus or minus 15 degrees for example, from the surface of the distal end portion 102 that lies adjacent the outer surface of the eye during use; this can be referred to as a side firing configuration. Different embodiments of the device 100a are described in United States Non-Provisional Patent Application No. 18 / 770,797 and also United States Provisional Patent Application No. 63 / 670,850 filed on July 12, 2024, and titled “DEVICES AND METHODS FOR PRECISION ADVANCING NEEDLE WITH SENSING”, which are both hereby incorporated by reference in their entirety. However, the devices described herein may also allow for supraciliary use which may be used for delivery of treatment fluid, such as a viscoelastic, to the eye as a way to increase outflow and lower intraocular pressure for certain treatments, such as glaucoma for example, or provision of a drug.

[0084] Referring to FIGS. 5A-5C and 5E, the device may also be implemented, in at least one embodiment, having a certain needle tip design for preventing fluid backflow during operation. Each of FIGS. 5A-5C show, from left to right, a side perspective view, a front view, a side view and a rear view of a needle end portion. The various needle tip designs have certain bevels that are used so that the needle bore opening 504 can be buried deeper or more fully into a target region of the tissue, which can make it more difficult for the fluid to reflux (i.e. leak or backflow) due to a larger amount of tissue applying resistive pressure around the opening 504 of the needle 101 . This is partly based on the angle a of the bevel and needle opening with the 90 degrees edge of the needle, the longitudinal extent le (or axial length) of the needle opening examples of which are shown in FIG. 5A, and the needle tip trajectory during insertion. The angle a, and the longitudinal extent can be affected by having different shapes / bevels for the needle opening as explained below. The needle tip designs described herein may also be applied to many other applications in the eye and elsewhere in which backflow is a concern.These needle tip designs may also be advantageous in any application where the needle bore opening is to be placed in a small target location, whether for fluid injection or for fluid drainage.

[0085] The needle tip designs include a “primary needle bevel”, e.g., the needle bevel at the needle tip, for penetrating the sclera wherein any combination of the needle bevel, the needle shape and the needle insertion trajectory have a geometry for reducing fluid backflow as described in various embodiments herein and alternatives thereof. The needle bevel may be formed as a cut across a tubular needle blank such that the needle bevel is bounded by a plane that is tangent to needle bevel perimeter at an angle with respect to the longitudinal axis of the needle, where in one example embodiment the angle may range from about 20 degrees (sharper) to about 30 degrees (blunter), and in other embodiments may be more or less sharp or blunt. The needle bevel as it is cut through the tubular needle body causes the needle lumen (or “bore”) to have an ellipticallike shape (e.g., a “needle bore ellipse”) with a major diameter in a plane parallel with the longitudinal axis of the needle body. An example of this is shown in FIG. 5A.

[0086] During injection of a fluid into a tissue, leakage can occur when there are gaps between the needle shaft near the needle bore opening 504 and the surrounding tissue being punctured. Gaps can be detrimental as loss of fluid can make it difficult to provide proper treatment, such as to create a bleb during the SCS procedure when treating retinal tears / detachment, due to an insufficient level of pressure required to open up the space against intraocular pressure.

[0087] When injecting fluid into the suprachoroidal space 103 or any other thin space within or between tissue layers, the axial length of the needle bore 504 opening is the major diameter of the needle bore ellipse and may be selected to reduce or prevent backflow. For example, when part of the needle bore opening 504 is outside of the eye surface and fluid is injected, some of the fluid may leak outside the eye or be delivered to the wrong location rather than flow into the desired target region. Additionally, a long bore opening means more of the distal surface 509 of the needle tip must pass the sclera and / or other adjacent tissue layers before the proximal end of the bore opening 508 is fully in the SCS 103 or other target location. In some embodiments, a very sharp tip maybe used to enable easy passage of the tip of the needle 101 through tissue without significant deflection of the tissue away from the tip of the needle 101 and tearing, but as described, it is preferable for the bore opening 504 to be dimensioned so that the entire bore opening can mostly or substantially fit within a thin / narrow / small target space or for the bore opening to be shorter than the thickness of the sclera or other target region. This principle of the needle bore opening fitting within a target region due to size and / or shape of the needle tip bevel and / or the angle of the insertion path / trajectory to the target region is applicable for deploying a medicament, gel, treatment liquid or other substance to the target region as well as draining fluid from the target region. For example, in FIG. 5D, the axial extent of the bore opening is too large such that it traverses to different tissue regions of the eye while in FIG. 5E the axial extent, shape and / or angle of the needle opening / bore is selected so that the needle bore fits entirely or mostly within one tissue layer rather than extending into an adjacent tissue region / layer. To achieve this, yet also achieve a sharp needle tip, at the tip region the needle bevel tip angle may be sharper, such as 12 degrees, for example, and then as the bevel recedes from the needle tip the angle may be increased to be blunter, such as 90 degrees, for example, to intersect the needle shaft opposite the needle tip, where the total axial length of the bevel along the longitudinal axis of the needle shaft is on the order of one needle diameter. A base angle may be 45 degrees as a compromise between reducing the force needed to insert the needle tip into a particular / desired tissue region and reducing the major diameter of the needle bore ellipse to minimize leakage outside of the intended injection region for the medicant, treatment fluid or substance that is being injected.

[0088] A curved needle bevel design is shown in FIG. 5A, for example, with the needle bevel having a circular arc profile. In some embodiments, the profile may instead be elliptical, parabolic, brachistochrone, other cycloid or defined by another polynomial curve, or another curve profile, including a multi-segment bevel with each segment having a different curve profile, in order to facilitate easy insertion of the needle through tissue by making the tip sharp (e.g. have a shallow angle that is formed at the very tip of the needle between the side wall of the needle and the bevel), examples of which are shown in FIGS. 5A and 5E, while reducing the bevel opening length compared to that of a singlestraight bevel with equivalent sharpness (e.g., angle), although in other embodiments a single straight bevel may still be used with other features described herein, which may be beneficial to reduce manufacturing complexity or cost, such as when the target space / region is large enough to fit a single straight bevel tip with enough sharpness to penetrate to the target region. The bevel opening length is defined as the longest distance from one point (e.g. location) such as a proximal location 508 on the bevel to a directly opposing point such as a distal location 510 on the bevel (e.g., see the front view (second image from the left) in FIG. 5A where this length is shown as le). A single straight bevel can still be used as long as the insertion force is low enough to not cause excessive tenting of the tissue and the bevel length is short enough so that preferably the approximate entire needle bore opening is in the target tissue region when the needle tip is approximately in the target space. Tenting of the tissue is when the needle tip pushes against a tissue surface and rather than be penetrated the tissue surface moves in the same direction as the needle is being inserted so that a portion of the tissue around the needle tip resembles the sloped upper surfaces of a tent. However, multi-angle bevels (e.g., multiple bevel segments with different angles an example of which is shown in FIG. 5B) may give advantages by lowering insertion force and maintaining a short bevel length.

[0089] In another embodiment, as shown, for example, in FIG. 5B, the needle 500b may have multiple portions with distinct (e.g., different) linear slopes of the bevel 503. Although the needle design 500b is an example with two segments 503a and 503b having different slopes, in some embodiments, the multi-angle (e.g., multi-slope or piecewise linear) needle bevel 503 may have three or more segments with different slopes. Here the bevel may be referred to as a multi-segment bevel or piece-wise linear bevel. For these needle tip designs, the tip of the needle 500b is preferably as sharp as a straight bevel with the same slope (i.e. angle) as the segment that is closest to the tip (e.g., the example angle of 12 degrees from normal in the second rightmost image in FIG. 5B), which is the distal most segment, which in this example is segment 503b, but by having the proximal segment 503a (or multiple more proximal segments in embodiments with 3 or more segments) with larger (and less sharp) angles (e.g., the example angle of 45 degrees from normal in the second rightmost image in FIG. 5B) the needle bore opening504 is significantly shorter overall compared to a single bevel with the same slope as the distal segment, where the distal segment is similar to a typical hypodermic 12 degree needle tip shown in Figure 5D, so that the entire needle bore 504 may be inside the sclera (~1 mm thick) when injecting just past it into the SCS as shown in FIG. 5E (the needle bore may be adapted to fit totally within other tissue regions rather than the sclera in other applications). In other multi-segment bevel embodiments, some of the segments may be straight bevels and some may be curved bevels.

[0090] In at least one alternative embodiment, there may be additional lancet or back- bevel cuts or facets, examples of which may be grinds, cuts, tapers, abrasions, facets, finishes, notches, slits, trims, or etches, that may be created using metal removal operations that are deployed on the sides 505 of a distal-most portion of a needle bevel or at an angle from the needle face along the needle bevel perimeter to further sharpen the needle to a point at the tip 509 of the needle for easier penetration into the eye or another target region. The side bevel cuts may be planar but may also be multifaceted where the angle of the plane with respect to the needle bevel plane and the longitudinal axis may vary. For example, the bevel cuts may be continuous (e.g., blended from one surface to another) or discrete (demarcated segments).

[0091] In at least one embodiment, the one or more side-bevel cuts (e.g., “lancet cuts”) may form from an acute to obtuse angle with respect to a plane tangent to the face of the needle bevel, the angle ranging from between about 10 and about 150 degrees, where an obtuse angle provides for a sharper edge and tip to reduce penetration force. An example of a needle tip 509 with a lancet or back-bevel cut is shown for needle 500c in FIG. 5C.

[0092] As shown in FIGS. 5D-5E, a device having a needle tip with different structure (e.g., bevel) can puncture the target tissue differently depending on the needle tip design. The needle tip may have a bore opening with a length, as in the embodiment shown in FIG. 5D, that extends past the SCS for a simple, straight 12-degree bevel with proximal and distal points 508d and 51 Od. In such cases the delivery of the treatment fluid would not be restricted to the SCS, which results in less effective treatment and a waste of some of the treatment fluid, and there is the potential for the needle to penetrate and causedamage to tissue or other structures beyond the SCS. In contrast, for the example embodiment shown in FIG. 5E, a curved bevel cut having proximal and distal points 508e and 51 Oe that starts at a 12-degree angle at the tip 509 and gradually shallows out to 45- degrees at the proximal end / point 508e will have a shorter bore opening that may fit totally within the SCS while maintaining the same sharpness and ease of penetration of a needle tip having the same 12-degree angle at the tip but a longer bore opening. Accordingly, a distal segment of the bevel can have a shallow angle of about 10 to about 30 degrees, for example, to increase sharpness while one or more proximal regions of the bevel can have a larger angle to reduce the size of the needle bore opening. In general, it is desirable for the tip of the needle to be as sharp as possible (or as sharp as needed) and have the bevel angle for one or more proximal segments of the bevel to be larger than the bevel angle at the distal segment at the needle tip. As a general design principle, the needle bevel length optimization can be thought of as trying to maximize the slope (making the needle sharper) near the distal needle tip while keeping the total axial length of the tip (e.g., the needle bore opening length) as short as a similarly less sharp needle such as but not limited to a 45-degree bevel, for example. In at least one embodiment, one can: a) select a desired bore opening that may be the largest bore opening that may fully or substantially fit within the target region, b) select a bevel angle for the needle tip (e.g., for the bevel segment that includes the needle tip) to provide a desired tip sharpness used to penetrate the tissue, c) select the remaining number of bevel segments, and d) select the bevel angles and / or bevel shapes for each of the remaining bevel segments to obtain the desired bore opening length.

[0093] It should be noted that in at least one embodiment, depending on the size of the target region, it may be possible to use a bevel having a single straight segment where the angle of the bevel near the needle tip provides the needed sharpness to puncture through one or more layers of tissue to arrive at the target region while the length of the needle bore due the bevel angle is small enough to fully fit within the target region so that any dispensed / ejected medicant or treatment fluid just enters the target region. Other embodiments may combine the single straight bevel needle tip with other aspects of the teachings herein such as a tapered needle shaft and / or an actuation assembly thatcauses an extendable needle to be deployed / advanced to follow a curved needle insertion trajectory when the needle is inserted into the eye or other tissue.

[0094] In another aspect of the teachings herein, in at least one example embodiment, as shown in FIG. 6A, the needle shaft adjacent to the needle bore opening 504 can be adapted to have a desired shape, such as a tapered shape, an example of which is distal needle shaft portion 601 . For example, the needle may have a tapered needle shaft that transitions from a larger proximal diameter (e.g. toward the base of the needle) to a smaller distal diameter (e.g. toward the tip of the needle) for stretching adjacent proximal tissue when the needle tip is inserted into the target region thereby improving sealing around the needle shaft at tissue that is adjacent to the needle insertion trajectory. This change in diameter may be accomplished by grinding down the needle outer surface. As the needle 600 is inserted into the tissue, the needle shaft 601 wedges and locally stretches the tissue to preload the tissue and prevent the tissue from moving away from the needle tip as the needle tip is further inserted to penetrate the tissue. The local stretching of the tissue is preferably done gradually as the needle penetrates the tissue to help create a seal around the needle injection location. This action may also create a seal around the shaft of the needle 600, i.e., along the path of the needle through the tissue from the insertion point to the target location / target region. In at least one embodiment, the taper 601 may run along the entire length of the needle 600. In at least one other embodiment, the taper 601 may start part way down the needle shaft 600 and extend all the way towards the tip of the needle (e.g., FIG. 6A). In some embodiments, whether the taper may begin at the base of the needle and extend to the needle tip, or the taper may begin at the base of the needle and continue part way down the length of the needle shaft, or the taper may start part way down the length of the needle shaft and may extend all the way to the tip of the needle such as to point 600b on the needle shaft. In at least one other embodiment, the taper may occur only near the base (e.g. proximal end) of the needle 600 to act as a plug near the insertion point of the needle when the needle is fully inserted. This taper can be made by swaging the needle, starting at a slightly larger diameter needle then squeezing it down to the desired diameter, or by thinning the outer wall of the needle, leaving a transition region (e.g., tapered region)between the new needle diameter and the original needle diameter. Another example of a tapered needle shape is shown in FIG. 6B for needle 601 that has been inserted through the sclera 104 into the SCS 103. The taper in FIG. 6A continues toward the end of the needle shaft, ending at the needle tip (e.g. the distal portion of the needle containing the needle bore opening and bevel) while the taper in FIG. 6B ends at a location along the needle shaft that is more proximal to the tip of the needle 600’.

[0095] In embodiments with a tapered needle shaft, the taper may be linear or may be defined by a polynomial when transitioning from one needle outer diameter to another needle outer diameter. Tapers may be located at one axial location of the needle shaft, multiple locations, or continuously along the length of the needle. Multiple “steps” in the taper may, for example, be favorable in order to prevent individual tissue types I tissue layers from sliding over the needle by providing different amounts of resistance based on diameter. In at least one alternative embodiment, there may be a “notch” along the needle shaft where the needle diameter decreases and then increases again, or a “bump” or a bulge along the needle shaft where the needle diameter increases then decreases again. This may help hold the tissue at one area of the needle and thus control the final location of the needle bore opening more precisely with respect to the target tissue I target region.

[0096] In another aspect of the teachings herein, in at least one example embodiment, as shown in FIGS. 7A-7C, a needle assembly 700 may have an indenter 703 (or indenting mound), which may also be referred to as a boss or post, around the needle extension point / location 702 where the needle tip and a variable portion of the needle shaft is extended from inside of the device to the outside of the distal end portion of the main body of the device during use. The indenting mound 703 around the needle extension point 702 can cause local deformation and stretching of the tissue that it contacts. This may make the tissue surface taut and prevent the needle 101 from causing further deflection (e.g., tenting) of the tissue as it advances. In other words, the indenter 703 is adapted to locally stretch (preload) the surface of the eye when the instrument tip is pressed against the exterior of the eye to reduce local deflection of the surface of the eye as the needle penetrates the eye; thereby reducing the “tenting” effect and resultant sudden uncontrolled “punch through” of the needle tip past the target region. Theindenting mound 703 can reduce the force required to insert a needle tip through the tissue compared to where the needle is directly inserted in the eye (i.e., without the indenting mound 703). For example, the indenting mound (also referred to as an indenter) 703 may have a flat face, or a ring-shaped face (e.g., toroid) which will make contact with the eye over a smaller surface area, compared to a flat face, thereby creating a greater local pressure (since pressure is equal to the force applied by the surgeon divided by the contact area with the eye), and thus provide a tighter seal when the needle penetrates the surface of the eye or outer layer of other tissue in other applications.

[0097] In some embodiments, the indenter 703 may be, for example, a stiff plastic part built into (i.e., integral or attachable to) the outer body of the device housing using the same material or a different material. In at least one embodiment, the indenter 703 may be a separate rubber piece that is integral with or attached to the housing of the distal end portion of the main body of the device where the indenter 703 allows for providing compression when depressing the eye. For example, certain manufacturing techniques, such as 3D printing for example, may be used to make parts with different materials that are integrated together.

[0098] The indenter 703, can help prevent or reduce backflow and leakage by creating a tight seal at the interface where the needle 101 enters the eye. The hole / aperture / orifice 702 of the indenter 703 that the needle exits through is preferably as small as possible, for example from about 1 .1 to about 2 or 3 times the diameter of the needle in width and to reduce or eliminate gaps between the hole 702 of the indenter 703 and the outer circumference of the needle. Having a larger hole 702 in the indenter 703 allows for a larger range of manufacturing tolerance which makes the device easier and less expensive to make. However, a larger hole 702 gives more room for fluid to flow backwards up around the outside of the needle shaft, so the hole should be kept close in size to the needle diameter.

[0099] In at least one embodiment, the indenter 703 may be made of a resilient deformable material such as a soft rubber (e.g., Shore A hardness 20-60 rubber). If a soft (e.g., complaint) rubber is used the hole can be undersized or made into a slit that deforms as the needle passes through it. As the material is compressed through its thickness, itwill expand radially (i.e. , according to the Poisson ratio of the material) and fill any gaps where there may be tolerance space around the needle 101 and thus help reduce leakage of the injected fluid out of the eye or into unintended regions (e.g., regions that are not the target region) of the eye around the needle shaft. The indenter 703 may be in the form of a mesa having a height of about 0.5 mm to about 3mm and an outer diameter on the order of about 3 to about 5 mm and an inner diameter of about 1.1 to about 2 needle diameters. In this embodiment, the radial dimensions of the indenter 703 may be a bit smaller when the indenter 703 is made of material that is more deformable (e.g., the opening 702 can be made smaller without the risk of obstructing the needle during needle deployment). Alternatively, in at least one embodiment, the indenter 703 may also be made from a harder material (either hard rubber up to ShoreA 100 or even a plastic such as polycarbonate) when there is not a concern for fluid leakage around the needle and the intent is to indent the eye with the instrument tip to help anchor it in position and also deform the tissue layers to help with penetration.

[0100] In at least one embodiment, a hydrophobic coating may be applied along the outside of the needle to also make it less likely for a fluid to flow along the length of the needle and out of the eye or into a different region of the eye other than the target region. In addition, the hydrophobic coating may be selected to have one or more additional properties such as, for example, low friction (e.g., PTFE (polytetrafluoroethylene) which is a synthetic fluoropolymer known for its non-stick and heat-resistant properties) so that a low friction hydrophobic coating can also reduce frictional resistance to insertion of the needle by reducing friction between the needle and the tissue that it is surrounded by during insertion (e.g., between the needle and surrounding portion of the target object).

[0101] Another factor to consider in reducing backflow is to prevent or reduce the amount that the needle shaft stretches the eye tissue as this stretching may create a larger hole in the eye than the diameter of the needle as it advanced as shown in FIG. 8A. If an actuation assembly or other device design results in pivoting the needle as it is inserted into the eye, the pivot causes small amounts of movement of the needle shaft tangent to the eye at the entry point. A curved needle that advances along this path (i.e., needle trajectory), with the needle shaft and needle path both having a radius of curvaturewhose center point is the pivot point of the actuating beam, will create a curved hole having a size of the needle diameter through the sclera since the tangential shift of the needle shaft at the entry point is matched by the curved shape of the needle. This is advantageous since a straight needle, on the other hand, will create a larger hole that is stretched or torn to an oval shape with its major axis tangent to the sclera, since the needle shaft at the entry point will move tangentially relative to the insertion point as the insertion depth increases. The tangent movement can be calculated as (Length from the pivot center to the needle attachment point) * (l -cos(theta)) where theta is the angle the pivot moves through. For the dimensions shown in FIG. 8A, this is about 1 needle diameter of tangential movement, so the point where the needle enters the eye will shift 1 needle diameter, stretching the tissue as it moves (assuming the eye and device do not also move).

[0102] This tangential movement of a needle at the entry point may also be reduced by forcing the needle to follow a set path which holds the entrance point of the needle stationary with respect to the eye. For example, a straight path cut into the indenter or outside body of the device (either of which may be referred to as a deployment guide) constrains the needle from turning or shifting away from its original path. In order to not over-constrain the system, the needle bend must be left unconstrained so that the needle can bend and expand as it advances, which can be accomplished by making the needle out of a material with some flexibility (but still rigid enough to advance into the eye). The straight part of the needle that is at the surface of the eye then remains at the same position at the original entry point at the surface of the eye throughout the advancement of the needle, even though the portion of the needle entering the eye, as the needle tip is advanced, is straight instead of curved. An example of this is shown in FIG. 8B.

[0103] In another aspect, in accordance with the teachings herein, there is at least one embodiment, an example of which is shown in FIG. 8C, in which a device is configured to reduce backflow by directing fluid more tangentially into the target region of the eye rather than perpendicularly into the target region of the eye. The needle 1011 in FIG. 8C follows a more tangential (e.g., curved) needle insertion trajectory while the needle 101 p in FIG. 8C follows a more perpendicular (e.g., straight) needle insertion trajectory. In suchembodiments, the tip of the needle 1011 advances to a location which is angularly displaced with respect to the needle entrance location (i.e., the point at which the needle tip first entered the eye) thereby making the path that is travelled by the needle tip from the needle entrance at the surface of the eye to the needle entrance into the target region curved or angled rather than linear. This is beneficial since this also makes the path for any dispensed fluid that may leave the target region, e.g., back along the shaft of the needle to the exterior of the needle, to be curved or angled so that it is less direct and therefore harder for the treatment fluid to exit the eye or enter into a different region of the eye when there is pressure due to the tissues of the eye at the target location that may push the treatment fluid back along the path that the needle tip followed. When some of the treatment fluid may flow back to the exterior of the eye or into another region of the eye, due to this phenomenon, it is referred to as backflow and is undesirable. The curved needle insertion path I curved needle insertion trajectory followed by the needle tip during extension / deployment is advantageous since other / outer tissue layers of the eye may provide inward pressure at certain portion of this curved trajectory to prevent flow of the treatment fluid backwards and outwards. This is in contrast with using traditional needle deployment which involves the needle tip entering straight into the eye and following a straight linear path, in which it may be easier for any deployed treatment fluid or medicant to flow directly back through any gaps between the exterior of the needle shaft and the surrounding tissue back along the deployment path of the needle to another region of the eye or to the outside of the eye.

[0104] Accordingly, in at least one embodiment, an ocular treatment device may be configured in accordance with the teachings herein so that the tip of the needle and the portion of the needle shaft that enters the eye or other tissue follow a curved needle entry path during deployment. This may be implemented using a pivoting action for the needle support / holding member such as by way of a pivoting lever. Alternatively, in at least one embodiment, a curved needle deployment may be achieved by pushing a needle through a curved pathway / conduit / tube in a distal end portion of the device such that the needle plastically deforms as it goes through the curved pathway I curved conduit I curved tube and enters the eye along a curved path. For example, nitinol needles may be used insuch embodiments since they have a lower Young’s modulus that makes them more flexible and able to bend around a curve.

[0105] The curved needle insertion path / trajectory helps reduce the potential for lateral tearing or stretching of the sclera as the needle penetrates due to the pivoting action of the lever that pushes the needle through the sclera that the needle tip must travel through to get the entire needle bore into a target region, as described previously, where the target region may be the SCS 103, for example, or some other ocular tissue in other ocular applications or some other tissue region altogether in other applications. In at least one embodiment, the deployment path of the needle 101 can be made to curve so that the needle first enters approximately perpendicularly (i.e. , normal to within + / - 30 degrees of the surface of the sclera), making it easy for the needle tip to puncture the sclera and not be deflected or cause any tenting. After that the needle is deployed / extended such that the insertion path I trajectory followed by the needle tip curves along a predefined arc such as a circular arc, for example, ranging from about 3 mm to about 20 mm where the arc has a radius that is approximately equal to the distance from the needle tip to the pivot point of the actuating lever used in the actuation assembly for the needle to within plus or minus 5 percent, plus or minus 10 percent, plus or minus 15 percent or plus or minus 20 percent. Accordingly, the insertion trajectory is predefined. A very small needle trajectory curvature radius may be used to inject fluid where the needle lumen is near tangent to eye structures after insertion. For example, an actuation assembly such as that shown in the device embodiment of FIGS. 9A-9C (i.e., which causes the needle holder to be pivotably moveable) or a suitable embodiment from those described in U.S. provisional patent application 63 / 670,850. The needle holder is a part of the actuation assembly that the needle is attached to such as the pivot member 705). This embodiment also enables greater localization of the injection than purely tangential insertion of a straight needle since the position of the tip of the needle 101 when it reaches the target location does not move laterally significantly far from the initial insertion point / location on the eye due to the curved insertion trajectory that is used during needle insertion. Additionally, as the needle tip is extended, the curved insertion trajectory reduces tangential strain of the eye tissues present when a straight needle is being actuated with a pivot member, as the nature ofthe pivoting motion of this embodiment causes slight tangential motion with needle extension. In addition, this embodiment also retains the benefits associated when using a needle adapted for tangential deployment since the sharp tip is not pointed directly at the sensitive choroid tissues and is therefore less likely to penetrate the choroid and cause bleeding or other injury.

[0106] In at least one embodiment in which a curved needle insertion trajectory is used, the shape of the portion of the needle 101 that is deployed may be pre-made I predefined with a curved shape that approximately matches the shape of the curved deployment path (i.e. , the arc of the needle path and the curvature of the needle have approximately the same radius of curvature) to reduce the likelihood that the needle tip deviates from the intended curved needle insertion path / trajectory. Such curved needles may also prevent any tearing or stretching of the tissue as the needle 101 (e.g. , the needle tip and adjacent distal portion of the needle shaft) advances into the eye for reasons given earlier. This center of the arc for the curved needle deployment path is the pivot point of the needle holding member that is pivotable (e.g., a pivoting beam) such as in an example embodiment of an actuation assembly 700a shown in FIGS. 9A-9C. The actuation assembly 700a includes a pivot member 704 which may be a pin, swivel or pivot hinge that is pivotally coupled to both a lower needle holding member 705 and a upper beam 706 so that the lower needle holding member 705 pivots and moves from one side of the inner wall of the device housing (e.g., when the needle 110 is in a retracted position) to the opposite side of the inner wall of the device housing (e.g., when the needle is in an extended position) to move the needle tip from being just at the surface of the eye, to follow a curved path through the eye to reach the injection site / target location / target tissue. As shown in FIG. 9B, the needle 101 is in the retracted position and as shown in FIG. 9C, the needle 101 is in the extended position and follows a curved needle insertion path / trajectory. The needle insertion path radius of curvature is preferably selected to have enough needle length to adapt to many scleral thicknesses. If a smaller radius of curvature is used, the maximum depth of the needle 101 is limited, and a longer needle and more actuation range is needed to reach the same radial depth of insertion as a straight needle of the same length. It is also preferable that the lateral displacement ofthe needle tip when it reaches the target location does not move too far from the original position of the needle tip at the insertion location by using a curved insertion trajectory.

[0107] A slight angle, preferably up to about 30 degrees, for needle insertion into the eye allows some of the benefits of a tangential entry without the downsides. As the needle tip penetrates the eye and travels along the slightly curved path as determined by the pivot radius R, the needle bevel angle with respect to the spherical surfaces of the tissue layers of the eye allows the needle bore opening to advance through tissue more tangentially. Thus when first starting penetration, the needle tip longitudinal axis (axis tangent to the exterior cylindrical surface of the needle at the penetrating tip region, e.g., 500ta in FIG. 5B) may, for example, be about 30 degrees from perpendicular to the eye outer surface, but will rotate with the pivoting of the beam to become about 40 degrees or even 45 degrees from perpendicular to an interior surface (such as the retina) depending on the radius R and depth of penetration. This makes the tip less likely to penetrate the interior surface of a tissue layer such as the retina, for example, and thus for subretinal injections to be possible.

[0108] As such, the needle insertion trajectory can be made to curve more or less depending on the designed position of this pivot point, with a longer distance between the pivot point and the needle tip resulting in less curvature and a shorter distance between the pivot point and the needle tip resulting in more curvature. If the pivot point is moved further distally (e.g., close to the distal end portion of the device), the distance from the pivot to the needle attachment point will be shorter, and thus the radius of curvature of the needle insertion trajectory will be smaller to follow the circular arc that the end of the pivoting needle holding beam follows. Conversely, if the pivot point is moved closer proximally (e.g., further away from the distal end portion of the device), the distance from the pivot to the needle attachment point will be longer, and thus the radius of curvature of the needle insertion trajectory will be larger to follow the circular arc that the end of the pivoting needle holding beam follows. More curvature will allow for greater tangent final entry into the target region, but because the depth is not exactly known, the actuation assembly of the needle holding member is preferably configured so that that the arc that defines the curved needle deployment path is long enough to reach the desired space inthe target region where the medicant or treatment fluid is to be dispensed before the needle deployment path curves to the point where it becomes fully tangential and the needle tip no longer moves in the perpendicular direction as the needle is extended further. Whatever curvature is chosen, the needle itself preferably has the same curvature which is achieved during the manufacturing process for the needle; and by the needle having the same curvature as the path the tip will take as governed by the pivot radius R, the needle will not tear the opening in the eye as it is inserted to the depth desired for injection of fluid or for drainage of fluid as the case may be.

[0109] In another embodiment, the pivot point may be an approximate virtual pivot of a cantilever, flexure, or other actuating beam. A virtual pivot is an approximate center of rotation for a mechanism which is not itself a pivot such as a flexural hinge, for example. The virtual pivot of the flexural hinge can be calculated using Pseudo-Rigid Body Flexure methods. A cantilevered beam also has a virtual pivot. If one were to overlay a rigid bar linkage with a pivot, the cantilever very closely resembles the motion of the calculated virtual rigid mechanism as is shown in FIG. 9D. Accordingly, this design may be applied to one of the cantilever embodiments described in United States Provisional Patent Application No. 63 / 670,850 to maintain a curved needle insertion path without an actual pivot as is used in the embodiment shown in FIGS. 9A-9C.

[0110] In another aspect, the inventors have discovered that elastic properties of the tissues surrounding many potential target regions may make injection into them initially difficult but then easier once the tissue has been expanded, similarly to how it is difficult to start blowing up a balloon, but once it is started it gets easier. Accordingly, devices and methods are described herein to pre-expand the tissues upstream of the target location or pre-expand the target region itself with a displacement fluid including a gas such as air or CO2 or another sacrificial fluid such as water or saline before injecting the main medicant since using the main medicament for that purpose may increase cost and / or expose tissues to larger quantities or concentrations of medicament than desired.

[0111] In accordance with the teachings herein there is provided at least one embodiment, an example of which is shown in FIGS. 10A-10C, in which it may be advantageous for the ocular treatment device to start with delivering a fluid such as apressurized gas or liquid through the needle as the needle advances (e.g., as the needle tip is extended) towards the target region during use so that some of the tissue around the target region can be displaced which will reduce the chances that the tip of the needle will extend to a depth past the target region. For example, in situations where the target region is the SCS 103, when the SCS 103 is accessed by the tip of the needle and air or other gas or liquid is deployed / expelled from the tip of the needle, the air or other gas will open up a space around it by displacing the interface between the SCS and the choroid, pushing the choroid layer away from the tip of the needle and reduce the likelihood or prevent the tip of the needle from puncturing the choroid. When the operator sees a gas bubble forming, the flow of gas can be stopped and the medicant or treatment fluid can be delivered to the space / target region. The delivered gas will then quickly dissipate, leaving only the medicant or treatment fluid in the target region. The gas may be referred to as a displacement fluid and may be air, CO2, SF6 (Sulfur Hexafluoride), C3F8 (Perfluoropropane), C2F6 (Hexafluoroethane) or other gases that may be commonly used in pneumatic retinopexy. In other embodiments, the fluid can be a liquid instead of a gas.

[0112] An example embodiment of an ocular treatment device 1000 that can implement this, is shown in FIGS. 10A-10C, in which the device 1000 can use an air / fluid ampoule 1006’ rather than an ampoule or cartridge 1006 just containing one fluid. The ampoule 1006’ has two separate chambers separated by rubber bungs 1020 and 1022 where a sacrificial gas such as air 1026, or sacrificial liquid, may be included in the lower I distal chamber and a treatment fluid 102 can be placed in the upper I proximal chamber. The treatment fluid may be a medicant, gel or a substance, such as, but not limited to an ophthalmic viscoelastic fluid (OVF), a viscoelastic for SCV, hydrogels, spheres containing medication, medications / drugs / pharmaceuticals, gene therapies, steroids, or cell-based therapies. In other embodiments the two chambers may both include treatment fluids, and in other embodiments the device may have three or more separated chambers containing different combinations of sacrificial and treatment fluids. The device 1000 that is shown is just one example and the dual chamber ampoule 1006’ can be used with other device embodiments such as some of those that are described in United States NonProvisional Patent Application No. 18 / 770,797 and United States Provisional PatentApplication No. 63 / 670,850. It should be noted that the fluid in the lower chamber may refer to a gaseous or liquid substance.

[0113] Referring now to FIG. 10A, shown therein is the device 1000 that has a housing 1001 defining a main body and uses mechanical interfaces (e.g., manual input or control interfaces) on the device body 901 which interact with internal mechanisms (e.g., actuation structures) to allow a surgeon, physician or other operator to control the device 900. For example, a needle movement control mechanism may be implemented using a rotational knob 1002, dial or wheel which may be oriented in line with the longitudinal axis of the device body 1001 to provide continuous needle extension with fine control. The location of the knob 1001 near the distal end potion of the device 1000 allows the surgeon to control the needle position with one finger and a small amount of travel / movement of the finger. The device 1000 also includes a separate slider 1004 located more proximally than, and spaced apart from, the knob 1002 which allows for controlling the dispensing of gas and treatment fluid in a smooth motion. In alternative embodiments, other input mechanisms may be used including, but not limited to, mechanical buttons, knobs in different orientations and locations, or other user interfaces, for example.

[0114] The device 1000 employs a pivoted beam configuration in which a force to move the needle 101 is in the middle or at the proximal end of a needle support member 1012 which allows for the extension of the needle 101. A rotating cam 1010 is attached to the knob / wheel 1002 via a pin 1008 to directly apply force to the needle holding member 1012. A proximal section of the needle holding member 1012 is bifurcated to provide a central slot / cutout (not shown) that has a cross shape with side-cutouts with surfaces that are moveably engaged by the rotating cam 1010 such that when the knob 1002 is rotated the cam 1010 also rotates and since the cam 1010 has a non-circular profile, in that certain edges of the perimeter of the cam 1010 have an increasing radial extent from the center of the cam 1010, rotation of the cam 1010 causes the needle holding member 1012 to move. The ratio of the perimeters / areas of the larger knob 1002 and the smaller cam 1010 affects the control / granularity (e.g., step size) with which a user may extend / retract the needle 101 during use. The cam profile may in some embodiments be described as having a nautilus spiral profile.

[0115] The needle holding member 1012 has a pin 1014 which interfaces with the main body / housing of the ocular device 1000 at the distal end portion of the body / housing of the device to create a pivot point about which a distal portion of the needle holding member 1012 may rotate. This pivot point can be located along the neutral bending axis or, preferably on a side portion of the needle holding member 1012, which may also be referred to as a beam, that is opposite the side portion of the needle holding member 1012 where the needle 101 is disposed since this creates a larger bending moment and thus makes the needle holding member 1012 stiffer.

[0116] An elastic element 1016 is located above an upper surface of a proximal end portion of a member 1015 and a lower surface of an ampoule 1006 is above the elastic element 1016. A plunger 1019 is held in place from above the ampoule 1006. There is also a support member 1018 which may be a shoulder or rib that protrudes from a sidewall of the main body / housing 1001 to support the ampoule 1006 so that it does not move downward.

[0117] The needle holding member 1012 is also configured to push up on the lower surface of the ampoule 1006 as the beam / needle holding member 1012 is deform ed / actuated. In such embodiments, the proximal section of the needle holding member 1012 is only constrained horizontally by the inner surface of a housing sidewall so that it may slide vertically upwards when force is applied by the cam 1010 during needle deployment. A dispending needle 1028 may then puncture the lower end of the ampoule 1006.

[0118] The slider 1004 has a coupling member 1004c that is attached or coupled to a portion of the plunger 1019 such as a proximal end of the plunger 1019. The distal portion of the plunger 1019 may be disposed within the ampoule 1006 or make contact with an upper end of a flexible ampoule so that downward motion of the plunger 1019 causes an increase in pressure which will result in the treatment fluid moving through the needle conduit when the injection pressure is larger than a local pressure or resistance at the needle tip when it is inserted within a target location such as a location of the eye. As the slider 1004 is moved towards the distal end of the device 1000, treatment fluid in the ampoule 1006 is dispensed through the needle tip. Markings may be used along the sliderpath on the outside of housing of the device 1000 to indicate to the surgeon, physician or operator how much fluid has been dispensed / injected. Accordingly, the plunger 1019 may be axially displaced to move the contents of the ampoule to be delivered through the needle bore to the target location. The plunger 1019 and the slider 1004, along with the components that they are coupled with to dispense the anything from the needle, form the dispensing assembly.

[0119] In accordance with the teachings herein, in an alternative embodiment, an ampoule 1006’ having multiple chambers that house different fluids such as a treatment fluid and a gas, for example, may be used to deliver both the treatment fluid and sacrificial gas / liquid to the target region. For example, the ampoule 1016’ includes a first moveable member 1020, such as a bung, at a proximal portion to receive a downward force, represented by the arrow, from the plunger 1019 during use as well as provide an upper wall to define an upper end of a first chamber that contains a treatment fluid 1024. A second moveable member 1022, such as a bung, is used to define a lower end of the first chamber as well as an upper end of a second chamber that is below the first chamber. The lower end of the second chamber is defined by the lower end of the ampoule 1006’. The second chamber is used to contain a sacrificial gas 1026 such as air, for example, or a sacrificial liquid as described previously. As the plunger 1019 pushes on the proximal / upper bung 1020, this causes the bung 1020 to move downward which pressurizes the treatment fluid 1024 in the first chamber which also causes a distal / lower bung 1022 to also move downward thereby causing the gas 1024 in the lower chamber to pass through the dispensing needle 1028 that punctures the lower end of the ampoule 1006’. The gas 1024 then travels down a conduit not shown to the needle 101 where the gas is automatically injected first into the target region, and then when the gas is finished (e.g., fully dispensed), as the plunger 1019 continues to move downwards, the dispensing needle 1028 punctures the lower bung 1022 and the second fluid (e.g., treatment fluid) begins flowing through the dispensing needle 1028 to the needle 101 into the target region.

[0120] It should be noted that while the majority of the embodiments described herein were for devices where the needle is deployed from a lateral surface of the distal endportion of the main body of the device (e.g., referred to as a device having “side firing” where firing refers to needle deployment), it should be understood that some of the embodiments described herein also work for devices that employ “end firing” where the needle is deployed from an end face of a distal end portion of the device where the end face is intersected by a longitudinal axis of the distal end portion of the device.

[0121] While the applicant's teachings described herein are in conjunction with various embodiments for illustrative purposes, it is not intended that the applicant's teachings be limited to such embodiments. On the contrary, the applicant's teachings described and illustrated herein encompass various alternatives, modifications, and equivalents, without generally departing from the embodiments described herein. For example, while the teachings described and shown herein may comprise certain elements / components and steps, modifications may be made as is known to those skilled in the art. For example, selected features from one or more of the example embodiments described herein in accordance with the teachings herein may be combined to create alternative embodiments that are not explicitly described. For example, as will be clear to a person having ordinary skill in the art, the devices and methods described herein may be implemented using other additional combinations and permutations of the various features and functions presented including shape, form factor, needle position or orientation, conduits, adjustments, controls, actuators, indicators, guidance elements, fluids and other materials, procedure steps, and / or applications. All values and subranges within disclosed ranges are also disclosed. The subject matter described herein intends to cover and embrace all suitable changes in technology.REFERENCES

[0001] S. E. Hancock, C.-R. Wan, N. E. Fisher, R. V. Andino, and T. A. Ciulla, “Biomechanics of suprachoroidal drug delivery: From benchtop to clinical investigation in ocular therapies,” Expert Opin. Drug Deliv., vol. 18, no. 6, pp. 777-788, Jun. 2021 , doi:10.1080 / 17425247.2021 .1867532.[2] K. Y. Wu, J. K. Fujioka, T. Gholamian, M. Zaharia, and S. D. Tran, “Suprachoroidal Injection: A Novel Approach for Targeted Drug Delivery,” Pharmaceuticals, vol. 16, no. 9, Art. no. 9, Sep. 2023, doi: 10.3390 / ph16091241 . [3] R. H. Muni, I. M. Melo, A. Pecaku, A. Mannina, H. Batawi, and A. Bansal, “In-OfficeSuprachoroidal Viscopexy for Rhegmatogenous Retinal Detachment Repair,” JAMA Ophthalmol., Aug. 2023, doi: 10.1001 Zjamaophthalmol.2023.3785.

Claims

CLAIMS:1 . A device for injecting medicant, gel, treatment fluid or a substance into a target region in a target object, wherein the device comprises: a housing defining a main body and a distal end portion; a needle at a distal end portion of the main body of the device, the needle having a needle tip with a needle bore opening for injection into the target region and the needle being moveable; an actuation assembly for deploying the needle so that the needle tip follows a needle insertion trajectory to the target region; and a dispensing assembly for moving the medicant, treatment fluid or substance to the needle tip during injection, wherein the needle and / or device is adapted to reduce backflow or leakage of the medicant, gel, treatment fluid or substance during delivery by having: (a) a needle shape for the needle tip and / or a needle shaft, and / or (b) the needle insertion trajectory that are adapted to place substantially all of the needle bore opening in the target region and reduce gaps between the needle and surrounding portion of the target object through which the needle is inserted.

2. The device of claim 1 , further comprising an ampoule containing the medicant, gel, treatment fluid or substance, the needle being coupled to the ampoule via a needle conduit; and a dispensing assembly for moving the medicant, treatment fluid or substance from the ampoule to the needle tip during injection.

3. The device of claim 1 or claim 2, wherein the device further comprises a needle holding member that is disposed within the housing and the needle is located at a distal portion of the needle holding member, wherein the actuation assembly is adapted to move the needle holding member to extend the needle from within the housing to outside of the housing during needle deployment.

4. The device of claim 3, wherein the needle holding member has a pivot point and is pivotable to cause the needle to follow a curved insertion trajectory during insertion tothe target region, and wherein a distance from the pivot point to the needle tip defines a radius for an arc of the curved insertion trajectory.

5. The device of claim 4, wherein the distance between the pivot point of the needle holding member and the needle tip is selected to predefine the curved insertion trajectory to cause the needle tip to enter the target region to within + / - 30 degrees of a normal of the surface of the target region.

6. The device of claim 4 or claim 5, wherein the needle shaft has a curved shape with a radius of curvature that approximately matches the radius of curvature of the curved needle insertion trajectory.

7. The device of any one of claims 1 to 6, wherein the needle tip has a needle bevel with at least one bevel segment having a curved bevel.

8. The device of claim 7, wherein the at least one needle bevel segment is circular or is a polynomial curve.

9. The device of any one of claims 1 to 6, wherein the needle tip has a needle bevel with at least one bevel segment having one or more straight bevel cuts.

10. The device of claim 7, 8 or 9, wherein the needle bevel or the one or more straight bevel segments form an angle between about 10 and about 60 degrees, or about 10 degrees to about 45 degrees, or about 25 to about 30 degrees.

11. The device of claim 9 or claim 10, wherein the needle bevel has two or more segments including a distal segment with a first angle or first curve for a desired sharpness of the needle tip and a proximal segment having a second angle or second curve that is greater than the first angle or the first curve to reduce the length of the needle bore opening.

12. The device of any one of claims 1 to 11 , wherein the needle has a tapered needle shaft for stretching portions of the target object that are adjacent the needle shaft whenthe needle is inserted into the target region thereby improving sealing around the needle shaft at the adjacent portions of the target object.

13. The device of claim 12, wherein the taper has a linear, curved, or irregular profile in one or more steps along one or more portions of the needle shaft.

14. The device of claim 12 or claim 13, wherein the taper includes a notched portion, a bumped portion, or a flanged portion.

15. The device of any one of claims 1 to 14, wherein the needle is located at a lateral surface of the distal end portion of the main body of the device where the lateral surface is used to contact the surface of the target object.

16. The device of claim 15, wherein the target object is convex and the lateral surface has a concave shape to distribute applied pressure to a surface of the target object during needle insertion.

17. The device of claim 16, wherein the device comprises an indenter at the distal end portion of the device so that the indenter surrounds an exit location of the needle to form a seal around a needle entry point at a surface of the target object when the needle is deployed.

18. The device of claim 17, wherein the indenter is adapted to locally stretch the surface of the target object to reduce deflection of the surface of the target object as the needle is inserted into the target object.

19. The device of claim 17 or claim 18, wherein the indenter is shaped as a boss, a mesa or a rounded post.

20. The device of any one of claims 17 to 19, wherein the indenter is made of a resilient compressible material.

21. The device of any one of claims 1 to 20, wherein the needle is deployed from a lateral surface of the distal end portion of the main body of the device or the needle isdeployed from an end face of a distal end portion of the device where the end face is intersected by a longitudinal axis of the distal end portion of the device.

22. The device of any of claims 2 to 21 , wherein the ampoule has multiple chambers with a distal chamber including a displacement fluid and a proximal chamber including the medicant, the gel, the treatment fluid or the substance.

23. The device of claim 22, wherein the dispensing assembly includes a plunger that when actuated causes deployment of the displacement fluid through the needle bore followed by deployment of the medicant, the gel, the treatment fluid or the substance through the needle bore.

24. The device of claim 23, wherein the ampoule is compressible by the plunger, or the plunger is configured to enter into a proximal end of the ampoule during deployment of the displacement fluid, followed by deployment of the medicant, the gel, the treatment fluid or the substance.

25. The device of any one of claims 22 to 24, wherein the displacement fluid is air, CO2, SF6, c3F8 or a liquid.

26. The device of any one of claims 1 to 25, wherein the target object is an eye.

27. The device of claim 26, wherein the target region is a suprachoroidal space, a subretinal space, or a supraciliary space.

28. A method for injecting medicant, gel, treatment fluid or a substance into a target region in a target object using a device that is defined according to any one of claims 1 to 27, wherein the method comprises: inserting a needle having a needle bore opening into the target object so that the needle bore is contained within the target region; and dispensing the medicant, gel, treatment fluid or a substance into the target region.

29. The method of claim 28, wherein the needle is deployed so that the needle tip follows a curved insertion trajectory to the target region, and wherein a distance from a pivot point to the needle tip defines a radius for an arc of the curved insertion trajectory.

30. The method of claim 28, wherein the needle is deployed so that the needle tip follows a curved insertion trajectory to the target region that is defined to cause the needle tip to enter the target region to within + / - 30 degrees of a normal of the surface of the target region.31 . The method of any one of claims 28 to 30, wherein the method includes deploying a displacement fluid into the target region before deploying the medicant, gel, treatment fluid or a substance into the target region.

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