Syringe adapter, injection assembly and use method

Abstract

The invention relates to an injector adapter, an injection assembly and a using method. The injector adapter comprises a connecting piece, and a cavity is formed in the connecting piece; the guide pipe penetrates through the connecting piece and penetrates through the cavity, and the pipe wall, located in the cavity, of the guide pipe is provided with a penetrating channel; the elastic sheath is located in the cavity, the elastic sheath is arranged outside the catheter in a sleeving mode, a potential gap cavity is formed between the elastic sheath and the catheter, and the potential gap cavity is in fluid communication with the catheter through the penetrating channel. The injector adapter can be used in cooperation with an existing injector, so that an operator can more visually judge whether a needle head penetrates through the sclera to reach the suprachoroidal space or not so as to guide the operator to conduct medicine injection, and the injection convenience of the operator is remarkably improved.

Description

Technical Field

[0001] This application relates to the field of ophthalmic medical device technology, and in particular to a syringe adapter, injection assembly, and method of use. Background Technology

[0002] Currently, fundus diseases are one of the leading causes of irreversible visual impairment or damage, mainly including neovascular age-related macular degeneration, diabetic retinopathy, diabetic macular edema, central retinal vein occlusion, and branch retinal vein occlusion. In the treatment of these eye diseases, tissue barriers (such as the cornea, conjunctiva, blood-aqueous barrier, and blood-retinal barrier) limit drug delivery to the fundus. Conventional delivery methods, such as topical administration and intravitreal injection (IVT), while convenient, are not efficient or safe in delivering drugs to the lesion site.

[0003] Drug delivery to the eye has always been a challenge due to the unique structure of the eye. Delivery to the suprachoroidal space (SCS) is particularly difficult, determined by its structure. The suprachoroidal space is a potential cavity between the sclera and choroid, with no apparent gap in the absence of fluid and / or tissue separation. It becomes visible in this area when fluid or other materials accumulate between the choroid and sclera. Therefore, the suprachoroidal space is intentionally created by delivering, injecting, and / or infusing drug formulations into the suprachoroidal space to induce fluid accumulation, thereby separating the choroid from the sclera. Suprachoroidal drug delivery may result in local choroidal hemorrhage and retinal damage during injection; additional complications may occur, such as endophthalmitis, scleral ectasia, wound abscess, and occasionally, intraocular pressure elevation and cataracts.

[0004] Currently, during suprachoroidal injection, operators cannot visually determine whether the needle tip has reached the suprachoroidal space. They can only judge whether the needle tip has penetrated the sclera and reached the suprachoroidal space by controlling the needle tip length and the resistance of the plunger during injection. Patients of different ages exhibit significant differences in scleral thickness and density, and the scleral thickness also varies in different parts of the eye, resulting in different back pressures. Therefore, injecting medication into relatively dense ocular tissues (such as the sclera) requires more driving pressure to expel the medication from the needle than injecting it into the suprachoroidal space. This makes it difficult to accurately determine whether the needle tip has penetrated the sclera and reached the suprachoroidal space during microneedle injection, and this method is dependent on the doctor's skill level, making standardization difficult. Meanwhile, in order to ensure that the needle tip penetrates the sclera, doctors usually apply a force level to the syringe that is higher than the force that the user feels comfortable with, so that the tissue at the injection site is concave inward to shorten the path for the needle to reach the suprachoroidal space. However, at this time, the overload force often leads to subconjunctival diffusion or reflux of the drug, as well as adverse reactions such as subconjunctival hemorrhage and subconjunctival inflammation. Moreover, because doctors are unwilling to apply force to completely expel the drug, it further leads to insufficient drug dosage.

[0005] Meanwhile, suprachoroidal injection is an emerging precision intraocular drug delivery technique, and its safety and efficacy are highly dependent on the technique used, especially the speed of intraocular drug delivery. Injection that is too rapid or sudden drug release can cause a range of problems, from mild reversible reactions to serious, potentially blinding complications. For example, because the suprachoroidal space is a potential cavity with a limited capacity (approximately 100-200 microliters in humans), rapidly injecting a large amount of medication and instantly occupying the space can not only push the irido-lens septum forward and compress the retina and choroid backward, leading to a sharp increase in intraocular pressure (IOP), inducing adverse reactions such as acute ocular hypertension, vascular occlusion, and optic nerve damage; it can also generate strong shearing forces within the narrow suprachoroidal space, tearing tissue and causing ciliary body separation, severely affecting aqueous humor production, leading to long-term, refractory hypotension, and subsequently choroidal edema, wrinkling, and even macular degeneration. Furthermore, excessive injection pressure may puncture Bruch's membrane, accidentally injecting the drug into the subchoroidal space, thereby increasing the risk of bleeding and scarring. In extreme cases, excessive pressure may cause the needle tip to accidentally puncture the retina, resulting in an iatrogenic retinal tear or even penetrating the eyeball wall. Summary of the Invention

[0006] The purpose of this application is to overcome the shortcomings of existing injection devices that cannot intuitively and accurately determine the position of the needle in the eye, and to provide an ophthalmic syringe adapter, injection components, and a method of use.

[0007] In a first aspect, this application provides a syringe adapter, including a connector having a chamber; a catheter passing through the connector and through the chamber, the catheter wall located within the chamber having a through channel; and an elastic sheath located within the chamber and sleeved over the catheter, a potential gap cavity forming between the elastic sheath and the catheter, the potential gap cavity being fluidly interconnected with the catheter through the through channel.

[0008] The syringe adapter provided in this application can be installed between the syringe and the needle, and the syringe and the needle are connected by a conduit. Because the back pressure generated by different layers of the eye on the needle outlet (i.e. the needle tip from which the liquid flows out) is different (for example, when the needle tip is in the sclera, the back pressure generated by the needle tip is greater than when the needle tip is in the suprachoroidal space), the liquid in the syringe undergoes hydraulic changes due to the different back pressures it experiences during injection.

[0009] Because the catheter communicates with the potential gap cavity through a through-channel, when the hydraulic pressure inside the catheter is insufficient to inflate the elastic sheath and separate it from the catheter wall, the potential gap cavity is in a closed state, meaning the elastic sheath is in contact with the catheter wall and the volume of the potential gap cavity is close to zero. When the hydraulic pressure inside the catheter is sufficient to inflate the elastic sheath and separate it from the catheter wall, at least some of the fluid inside the catheter enters the potential gap cavity through the through-channel, causing the potential gap cavity to expand, and at this point, the potential gap cavity is in an open state.

[0010] When the needle tip penetrates different tissues, users can more intuitively judge whether the needle tip has penetrated the sclera and reached the suprachoroidal space by observing changes in the volume of the potential space, the expansion of the elastic sheath, or the entry of liquid into the potential space, so as to guide the operator to inject drugs.

[0011] Optionally, the syringe adapter is used to connect the syringe and the needle. When the needle tip is located in the suprachoroidal space, the injection pressure generated in the syringe is insufficient to inflate the elastic sheath, and at least a portion of the substance in the syringe can be output through the needle. When the needle tip is located in the sclera, the injection pressure generated by the syringe is sufficient to inflate the elastic sheath, and the potential space cavity receives at least a portion of the substance delivered from the syringe through the through-channel, preventing the substance in the syringe from being output through the needle.

[0012] When the needle tip is located in the suprachoroidal space at the target location, the injection pressure generated in the syringe is insufficient to cause the elastic sheath to expand and disengage from the catheter wall, and at least a portion of the substance in the syringe can be output through the needle.

[0013] When the needle tip is positioned within the sclera at the target location, the injection pressure generated by the syringe is sufficient to inflate the elastic sheath and disengage it from the catheter wall, opening a potential cavity and receiving at least a portion of the fluid being delivered from the syringe, preventing fluid from exiting through the needle. This prevents the injection pressure within the syringe from exceeding the tissue back pressure generated by the sclera, thus preventing leakage at the insertion site and subsequent reflux or subconjunctival diffusion.

[0014] In some embodiments of this application, a first region of the target tissue described herein has a first density, and a second region of the target tissue has a second density. The first density is higher than the second density.

[0015] In some embodiments of this application, a first region of the target tissue described herein generates a first back pressure at the needle tip; and a second region of the target tissue generates a second back pressure at the needle tip. The first back pressure is higher than the second back pressure.

[0016] The target tissue described herein can be the eye. Different tissue layers within the eye can have different densities. For example, the sclera generally has a higher density than the conjunctiva or the suprachoroidal space. Density differences in the target region or layer may generate different back pressures at the needle tip (i.e., the end of the needle where fluid appears). Therefore, injecting into relatively high-density ocular tissues (such as the sclera) requires greater injection pressure to expel the drug from the needle than injecting it into the suprachoroidal space. Optionally, the elastic sheath is a rubber component, a silicone component, a low-density polyethylene component, a polytetrafluoroethylene component, or a cellulose acetate component.

[0017] Optionally, the syringe adapter is used to connect the syringe and the needle, and to regulate the injection pressure between the syringe and the needle. This allows for effective control of the release rate of the substance in the suprachoroidal space, preventing excessively rapid release or sudden release.

[0018] When the needle tip is positioned within the suprachoroidal space at the target location, if the injection pressure exceeds the pressure threshold for the expansion of the elastic sheath, the elastic sheath expands, opening a potential gap cavity to receive at least a portion of the substance delivered from the syringe. This reduces the injection pressure, allowing for effective control of the release rate of at least a portion of the substance within the suprachoroidal space via the needle tip. If the injection pressure falls below the pressure threshold for the expansion of the elastic sheath, the elastic sheath closes the potential gap cavity, and at least a portion of the substance within the syringe is output through the needle. This prevents the injection pressure within the syringe from continuously increasing, which could lead to excessively rapid injection or sudden release of the substance, thus stabilizing intraocular pressure.

[0019] When the needle tip is positioned within the sclera at the target location, if the injection pressure exceeds the pressure threshold of the elastic sheath expansion, the potential cavity opens and receives at least a portion of the fluid delivered from the syringe, reducing the injection pressure within the syringe and preventing fluid from exiting through the needle. This prevents leakage from the insertion site due to the injection pressure exceeding the tissue back pressure generated by the sclera, thus avoiding reflux or subconjunctival diffusion.

[0020] Optionally, the elastic modulus of the elastic sheath is about 1 GPa or less, about 0.5 GPa or less, about 0.1 GPa or less, about 0.05 GPa or less, about 0.01 GPa or less, about 10 MPa or less, about 5 MPa or less, about 2 MPa or less, about 1 MPa or less, about 0.6 MPa or less, about 0.5 MPa or less, or about 0.3 MPa or less. In some embodiments, the elastic modulus of the elastic sheath may be about 1 GPa. In other embodiments, the elastic modulus of the elastic sheath may be about 0.5 GPa, or about 0.1 GPa, or about 0.05 GPa, or about 0.01 GPa, or about 0.005 GPa, or about 10 MPa, or about 5 MPa, or about 2 MPa, or about 1 MPa, or about 0.6 MPa, or about 0.5 MPa, or about 0.3 MPa.

[0021] Optionally, the pressure threshold for the expansion of the elastic sheath is not higher than the tissue back pressure generated by the sclera, and the pressure threshold for the expansion of the elastic sheath is not lower than the tissue back pressure generated by the suprachoroidal space.

[0022] The pressure threshold for the expansion of the elastic sheath can be selected from the range of 2-6 N applied by the user during injection. This force generates an injection pressure between approximately 100 kPa and approximately 500 kPa within the syringe. This injection pressure is sufficient to overcome the back pressure generated in the suprachoroidal space but insufficient to overcome the back pressure generated by the scleral tissue. Therefore, the pressure threshold for the expansion of the elastic sheath can be selected from between 100 kPa and approximately 500 kPa.

[0023] For example, in some embodiments, the pressure threshold may be approximately 100 kPa, 110 kPa, 120 kPa, 130 kPa, 140 kPa, 150 kPa, 160 kPa, 170 kPa, 180 kPa, 190 kPa, 200 kPa, 220 kPa, 240 kPa, 260 kPa, 280 kPa, 300 kPa, 320 kPa, 340 kPa, 360 kPa, 380 kPa, 400 kPa, 420 kPa, 440 kPa, 460 kPa, or approximately 480 kPa, including all ranges and values ​​therein. Optionally, the syringe adapter is used to connect the syringe and the needle. The elastic sheath can switch between a first configuration (in which the elastic sheath fits against the catheter wall and the potential space cavity is closed) and a second configuration (in which the elastic sheath expands and separates from the catheter wall and the potential space cavity is open). When the needle tip is located in the suprachoroidal space, the elastic sheath is in the first configuration, and at least a portion of the substance can be delivered from the syringe via the needle. When the needle tip is located in the sclera, the elastic sheath is in the second configuration, and the potential space cavity receives at least a portion of the substance delivered from the syringe through the through-channel, preventing the substance in the syringe from being output from the needle.

[0024] Optionally, the syringe adapter connects the syringe and the needle, and in response to the injection pressure between the syringe and the needle, causes the elastic sheath to switch between a second configuration and a first configuration, thereby regulating the injection pressure between the syringe and the needle. This effectively controls the release rate of the substance from the syringe into the suprachoroidal space.

[0025] When the needle tip is positioned within the suprachoroidal space at the target location, if the injection pressure exceeds the pressure threshold for the expansion of the elastic sheath, the elastic sheath transitions from a first configuration to a second configuration, opening the potential gap cavity to receive at least a portion of the substance delivered from the syringe, thus reducing the injection pressure. This effectively controls the release rate of the substance within the suprachoroidal space. If the injection pressure is below the pressure threshold for the expansion of the elastic sheath, the elastic sheath remains in the first configuration, closing the potential gap cavity, and at least a portion of the substance within the syringe is delivered via the needle. This prevents the injection pressure within the syringe from continuously increasing, which could lead to excessively rapid injection or sudden release of the substance, thereby stabilizing intraocular pressure.

[0026] When the needle tip is positioned within the sclera at the target location, if the injection pressure exceeds the pressure threshold for the elastic sheath to expand, the elastic sheath transitions from a first configuration to a second configuration. This opens a potential gap cavity and receives at least a portion of the fluid being delivered from the syringe, reducing the injection pressure within the syringe and preventing the needle from delivering fluid from the syringe. This prevents leakage from the insertion site due to the injection pressure exceeding the tissue back pressure generated by the sclera, thus avoiding reflux or subconjunctival diffusion.

[0027] Optionally, the connector may have a transparent viewing window, and / or the connector may be a transparent component, and / or the outer wall of the elastic sheath may have a prominent layer, and / or the syringe adapter may have a touch sensor for emitting a recognizable signal.

[0028] Specifically, the viewing window can be positioned on the connector opposite the chamber. Alternatively, the connector can be made of a transparent material. Using a viewing window or a transparent material facilitates observation of the expansion of the elastic sheath, allowing for quick assessment of whether the needle tip is in the suprachoroidal space at the target location.

[0029] By setting a conspicuous layer to increase the visibility of the elastic sheath, it is easier to observe the expansion of the elastic sheath and quickly determine whether the needle tip is in the suprachoroidal space at the target location.

[0030] A touch sensor is incorporated into the syringe adapter to emit a recognizable signal. Specifically, in one scenario, the touch sensor may include a conductive layer disposed on the outer wall of an elastic sheath, electrodes disposed within a chamber, and a response mechanism disposed within the syringe. When the elastic sheath expands, causing the conductive layer to contact the electrodes of the touch sensor, the internal circuitry of the touch sensor closes, resulting in current flow. This causes the response mechanism to emit a recognizable signal (e.g., an audible signal, a visual signal, etc.), allowing the user to quickly determine whether the needle tip is in the suprachoroidal space at the target location.

[0031] Specifically, another scenario could be a touch sensor comprising an electrode layer disposed on the outer wall of an elastic sheath, an electrode membrane disposed within a cavity opposite to the electrode layer disposed on the outer wall of the elastic sheath, and a response mechanism disposed in the syringe, wherein a certain insulating cavity is formed between the electrode layer and the electrode membrane. When the elastic sheath expands and causes the electrode layer to contact the electrode membrane, the circuit of the touch sensor closes and causes current to flow, causing the response mechanism to emit an identifiable signal, enabling the user to quickly determine whether the needle tip is in the suprachoroidal cavity at the target location.

[0032] Optionally, the syringe adapter is used to connect a needle, the elastic sheath expands to extend the needle tip into the suprachoroidal space; and / or, the elastic sheath contracts to retract the needle tip into the sclera.

[0033] Optionally, a flexible bottom is provided at the distal end of the connector, and / or a fluid-sealed cavity is provided between the connector and the needle, and / or a traction component is provided in the region of the cavity and the chamber.

[0034] Specifically, for example, the elastic sheath divides the cavity in the middle of the connector into a first chamber and a second chamber. At the distal end of the connector opposite the second chamber is a flexible bottom, which connects to the needle, allowing the needle hub to be fitted onto the catheter and move axially within the second chamber. The needle hub has a cavity configured to be fluid-sealed with the needle tube, ensuring that the distal end of the catheter remains within the cavity of the needle hub and in fluid contact with the needle tube. The first chamber corresponds to the potential gap chamber, and the second chamber is defined as the space within the cavity and outside the elastic sheath.

[0035] When the needle tip is located in the suprachoroidal space at the target location, the elastic sheath is configured in a first configuration, and at least a portion of the liquid in the syringe is output through the needle.

[0036] When the needle tip is located in the sclera at the target location, the elastic sheath changes from the first configuration to the second configuration. The liquid in the syringe enters the first chamber, which increases the air pressure in the second chamber, thereby driving the flexible bottom to move the movable needle hub to the distal end of the sleeve, so that the needle tip extends further into the suprachoroidal space at the target location.

[0037] When the needle tip extends and reaches the suprachoroidal space at the target location, the elastic sheath changes from the second configuration to the first configuration in the chamber, and the liquid in the first chamber flows out and is delivered to the suprachoroidal space via the needle.

[0038] When the elastic sheath transitions from the second configuration to the first configuration within the chamber, the air pressure in the second chamber is insufficient to resist the elastic force of the flexible base, causing it to retract and move towards the connector. This causes the needle tip to gradually retract along the needle path formed within the scleral tissue at the target location. This allows for further diffusion of the liquid in the suprachoroidal space and also makes the intraocular pressure more stable during liquid delivery within the syringe.

[0039] Optionally, the syringe adapter can also respond to the injection pressure between the syringe and the needle, causing the elastic sheath to switch between a second configuration and a first configuration to regulate the injection pressure between the syringe and the needle. This allows for effective control of the release rate of the substance within the syringe in the suprachoroidal space, preventing excessively rapid release or sudden release.

[0040] When the needle tip is located within the suprachoroidal space at the target location, if the injection pressure exceeds the pressure threshold for the expansion of the elastic sheath, the elastic sheath changes from a first configuration to a second configuration, opening the potential gap cavity to receive at least a portion of the substance delivered from the syringe, and reducing the injection pressure. This effectively controls the release rate of the substance within the suprachoroidal space, preventing excessively rapid release or sudden release. If the injection pressure is below the pressure threshold for the expansion of the elastic sheath, the elastic sheath is in the first configuration, closing the potential gap cavity, and at least a portion of the substance within the syringe is output via the needle.

[0041] When the needle tip is located in the sclera at the target location, if the injection pressure is higher than the pressure threshold for the expansion of the elastic sheath, the elastic sheath changes from the first configuration to the second configuration, opens the potential gap cavity and receives at least a portion of the liquid delivered from the syringe, reduces the injection pressure in the syringe, and prevents the liquid in the syringe from being output from the needle.

[0042] When the needle tip extends and reaches the target location in the suprachoroidal space, the fluid inside the needle automatically depressurizes and is injected into the suprachoroidal space. The injection pressure between the syringe and the needle decreases accordingly. The elastic sheath in the second configuration responds to the decrease in injection pressure and transitions to the first configuration to maintain the injection pressure in the first chamber higher than the pressure within the suprachoroidal space. This allows at least a portion of the material in the first chamber to be delivered to the suprachoroidal space via the needle tip until the elastic sheath adheres to the catheter wall of the connector, closing the potential gap cavity.

[0043] Optionally, the proximal end of the connector is an integral component with the syringe outlet end face.

[0044] Optionally, the syringe adapter interfaces with the syringe or needle in the form of a Luer connector or a through-hole connector.

[0045] Optionally, a fluid-sealed cavity is provided between the connector and the needle, the cavity being configured to house the needle hub, allowing the needle hub to be fitted onto the catheter and move axially within the cavity along the catheter. The needle hub contains a cavity configured to be fluid-sealed with the needle tube, ensuring that the distal end of the catheter remains within the cavity of the needle hub and is fluidly connected to the needle tube.

[0046] When the needle tip is located in the suprachoroidal space at the target location, the injection pressure generated in the syringe is insufficient to cause the elastic sheath to expand and generate enough air pressure in the cavity to push the needle hub to move along the catheter towards the distal end of the needle in the cavity, and at least a portion of the liquid in the syringe is output through the needle.

[0047] When the needle tip is located in the sclera at the target location, the elastic sheath expands to open the potential gap cavity to receive the liquid in the syringe, while generating sufficient air pressure in the cavity to push the needle hub along the catheter towards the distal end of the needle, allowing the needle tip to extend further into the suprachoroidal space at the target location.

[0048] When the needle tip extends to the suprachoroidal space at the target location, the fluid in the needle tip is released in the suprachoroidal space, reducing the injection pressure in the syringe.

[0049] When the injection pressure in the syringe is insufficient to resist the elastic force of the elastic sheath, the elastic sheath retracts elastically, forcing at least a portion of the material in the potential gap cavity to enter the catheter through the through-channel provided in the connector catheter, and then gently delivered to the suprachoroidal space through the needle until the elastic sheath adheres to the catheter wall of the connector and closes the potential gap cavity.

[0050] Optionally, the syringe adapter includes a traction component in the region of the chamber and the cavity. This traction component is configured to allow the needle hub of the needle to move axially within the cavity under the action of an elastic sheath. The needle hub contains a cavity capable of fluid-sealed connection with the catheter and allowing the catheter to slide axially within the chamber. This cavity is configured to fluid-sealed connection with the needle tube of the needle, enabling fluid connection between the catheter and the needle tube within the cavity.

[0051] When the needle tip is located in the suprachoroidal space at the target location, the injection pressure generated in the syringe is insufficient to cause the elastic sheath to expand and move the traction component toward the side wall of the connector, and at least a portion of the liquid in the syringe is output through the needle.

[0052] When the needle tip is located in the sclera at the target location, the elastic sheath expands to open the potential gap cavity to receive the liquid in the syringe, while the contact area between the traction component and the elastic sheath moves toward the side wall of the connector. This guides the distal end of the traction component to drive the needle hub to move along the catheter axis toward the distal end of the sleeve within the cavity, allowing the needle tip to extend further toward the suprachoroidal space at the target location.

[0053] When the needle tip extends to the suprachoroidal space at the target location, the fluid in the needle tip is released into the suprachoroidal space, reducing the injection pressure in the syringe.

[0054] When the injection pressure in the syringe is insufficient to resist the elastic force of the elastic sheath, the elastic sheath elastically retracts and fits against the conduit wall of the connector, closing the potential gap cavity. This forces the liquid in the potential gap cavity to enter the conduit through the through-channel provided in the connector conduit, and then deliver it to the suprachoroidal space through the needle.

[0055] Optionally, the syringe adapter can also respond to the injection pressure between the syringe and the needle by elastically expanding or contracting the elastic sheath to regulate the injection pressure between the syringe and the needle. This allows for effective control of the release rate of the substance in the suprachoroidal space, preventing excessively rapid release or sudden release.

[0056] When the needle tip is located in the suprachoroidal space at the target position, if the injection pressure reaches the pressure threshold for the expansion of the elastic sheath, the elastic sheath expands, opening the potential gap cavity to receive at least a portion of the substance delivered from the syringe, and the injection pressure is reduced. This allows for effective control of the release rate of the substance in the suprachoroidal space within the syringe. If the injection pressure is lower than the pressure threshold for the expansion of the elastic sheath, the elastic sheath adheres to the catheter wall, closing the potential gap cavity, and at least a portion of the substance in the syringe is output through the needle.

[0057] When the needle tip is located in the sclera at the target location, if the injection pressure reaches the pressure threshold for the expansion of the elastic sheath, the elastic sheath expands, opens the potential gap cavity and receives at least a portion of the liquid delivered from the syringe, and reduces the injection pressure in the syringe so that the liquid in the syringe cannot be output from the needle.

[0058] When the needle tip extends and reaches the target location in the suprachoroidal space, the fluid inside the needle automatically depressurizes and is injected into the suprachoroidal space. The injection pressure between the syringe and the needle decreases accordingly. The elastic sheath, which is in an expanded state, contracts in response to the reduced injection pressure, maintaining the injection pressure within the potential space cavity higher than the pressure within the suprachoroidal space. This allows at least a portion of the material in the first chamber to be delivered to the suprachoroidal space via the needle tip until the elastic sheath adheres to the conduit wall of the connector, closing the potential space cavity.

[0059] Optionally, the traction component is fixedly connected to the elastic sheath. When the elastic sheath elastically retracts to drain the liquid in the potential gap cavity into the catheter, the traction component moves toward the catheter, guiding the distal end of the traction component to drive the needle hub to move along the catheter axis toward the distal end of the sleeve within the cavity, so that the needle tip located in the suprachoroidal cavity gradually retracts along the needle path formed by the needle in the scleral tissue at the target location.

[0060] Optionally, the syringe adapter can be directly fitted into the distal end of the syringe, with the syringe adapter and the distal end of the syringe forming a fluid seal, allowing the liquid inside the syringe to be fluidly connected through the syringe adapter.

[0061] Optionally, the syringe adapter has a flexible catheter that is connected to the needle hub, and the catheter is always kept in fluid connection with the needle tube as the needle hub moves toward the distal end of the sleeve.

[0062] In a second aspect, this application provides an injection assembly, including the aforementioned syringe adapter, a syringe, the distal end of which is connected to the syringe adapter; and a needle, which is connected to the distal end of the syringe adapter; the syringe and the needle are fluidly connected through the syringe adapter.

[0063] When the needle tip is located in the suprachoroidal space at the target location, the injection pressure generated in the syringe is insufficient to cause the elastic sheath to expand and detach from the catheter wall, and at least a portion of the substance in the syringe is output through the needle.

[0064] When the needle tip is positioned within the sclera at the target location, the injection pressure generated within the syringe is sufficient to cause the elastic sheath to expand and detach from the catheter wall, receiving at least a portion of the substance being delivered from the syringe, preventing the liquid within the syringe from exiting through the needle.

[0065] The syringe adapter can also respond to the injection pressure between the syringe and the needle, causing the elastic sheath to expand or contract elastically, thereby regulating the injection pressure between the syringe and the needle. This allows for effective control of the release rate of the substance within the suprachoroidal space, preventing excessively rapid or sudden release.

[0066] When the needle tip is located in the suprachoroidal space at the target position, if the injection pressure reaches the pressure threshold for the expansion of the elastic sheath, the elastic sheath expands, opening the potential gap cavity to receive at least a portion of the substance delivered from the syringe, and the injection pressure is reduced. This allows for effective control of the release rate of the substance in the suprachoroidal space within the syringe. If the injection pressure is lower than the pressure threshold for the expansion of the elastic sheath, the elastic sheath adheres to the catheter wall, closing the potential gap cavity, and at least a portion of the substance in the syringe is output through the needle.

[0067] When the needle tip is located within the sclera at the target location, if the injection pressure reaches the pressure threshold for expansion of the elastic sheath, the elastic sheath expands elastically, opening a potential gap cavity and receiving at least a portion of the liquid delivered from the syringe, reducing the injection pressure within the syringe so that the substance within the syringe cannot be output from the needle.

[0068] Optionally, the needle includes a needle tube, a sleeve, an elastic element, and a needle hub; the proximal end of the needle hub is connected to the syringe adapter, the distal end of the needle hub is provided with a sleeve, an elastic element is provided between the sleeve and the needle hub, the needle tube is mounted on the needle hub, and at least a portion of the needle tube protrudes from the sleeve; the elastic element is configured to drive the sleeve to move towards the distal end when deformed under pressure, thereby further extending the length of the needle tube protruding from the sleeve.

[0069] Optionally, the syringe is provided with a plunger, the distal end of which is placed inside the syringe and the proximal end of which is placed outside the syringe. The plunger is configured to be subjected to force on the proximal portion of the plunger. The syringe, syringe adapter, and needle are configured such that (1) when the needle tip is placed in the suprachoroidal space at the target location, the injection pressure generated in the syringe is insufficient to cause the elastic sheath to expand and disengage from the catheter wall, thereby delivering at least a portion of the liquid from the syringe via the needle; (2) when the needle is located in the sclera at the target location, the injection pressure generated in the syringe is sufficient to cause the elastic sheath to expand and disengage from the catheter wall, thereby receiving at least a portion of the liquid delivered from the syringe, preventing the needle from delivering liquid from the syringe.

[0070] Optionally, the syringe adapter is configured with both the syringe and the needle such that:

[0071] The syringe adapter can also respond to the injection pressure between the syringe and the needle, causing the elastic sheath to expand or contract elastically, thereby regulating the injection pressure between the syringe and the needle. This allows for effective control of the release rate of the substance in the syringe within the suprachoroidal cavity.

[0072] When the needle tip is located in the suprachoroidal space at the target location, if the injection pressure reaches the pressure threshold for the expansion of the elastic sheath, the elastic sheath expands, opening the potential gap cavity to receive at least a portion of the substance delivered from the syringe, and the injection pressure is reduced, so that the release rate of the substance in the syringe in the suprachoroidal space can be effectively controlled.

[0073] If the injection pressure is lower than the pressure threshold for the expansion of the elastic sheath, the elastic sheath adheres to the catheter wall, closing the potential gap cavity, and at least a portion of the substance in the syringe is output through the needle.

[0074] When the needle tip is located within the sclera at the target location, if the injection pressure reaches the pressure threshold for expansion of the elastic sheath, the elastic sheath expands elastically, opening a potential gap cavity and receiving at least a portion of the liquid delivered from the syringe, thereby reducing the injection pressure within the syringe so that the substance within the syringe cannot be output from the needle.

[0075] When the needle tip extends and reaches the target location in the suprachoroidal space, the liquid inside the needle is depressurized and automatically injected into the suprachoroidal space. The injection pressure between the syringe and the needle decreases accordingly. The elastic sheath, which is in an expanded state, contracts in response to the decrease in injection pressure to maintain the injection pressure in the potential space cavity higher than the pressure in the suprachoroidal space. This allows at least a portion of the material in the potential space cavity to be delivered to the suprachoroidal space via the needle tip until the elastic sheath adheres to the catheter wall of the connector and closes the potential space cavity.

[0076] Optionally, the syringe includes a plunger with its distal end inside the syringe and its proximal end outside the syringe. The plunger is configured to be subjected to force on its proximal portion. The syringe, syringe adapter, and needle are configured such that:

[0077] (1) When the needle tip is located in the suprachoroidal space at the target location, the elastic sheath is configured in a first configuration to deliver at least a portion of the liquid from the syringe via the needle;

[0078] (2) When the needle tip is located in the sclera at the target location, the elastic sheath is configured to change the chamber between the first and second configurations. The liquid in the syringe enters the first chamber, which increases the air pressure in the second chamber and drives the distal end of the connector to extend the needle tip further into the suprachoroidal space at the target location.

[0079] (3) When the needle tip extends and reaches the suprachoroidal cavity at the target location, the elastic sheath is configured to change the chamber between a second configuration and a first configuration, and the liquid in the first chamber flows out and is delivered to the suprachoroidal cavity via the needle.

[0080] Optionally, the syringe includes a plunger with its distal end inside the syringe and its proximal end outside the syringe. The plunger is configured to be subjected to force on its proximal portion. The syringe, syringe adapter, and needle are configured such that:

[0081] When the needle tip is located in the suprachoroidal space at the target location, if the injection pressure reaches the pressure threshold for the expansion of the elastic sheath, the elastic sheath expands, opening the potential gap cavity to receive at least a portion of the substance delivered from the syringe, and the injection pressure is reduced, so that the release rate of the substance in the syringe in the suprachoroidal space can be effectively controlled.

[0082] If the injection pressure is lower than the pressure threshold for the expansion of the elastic sheath, the elastic sheath adheres to the catheter wall, closing the potential gap cavity, and at least a portion of the substance in the syringe is output through the needle.

[0083] (2) When the needle tip is located within the sclera at the target location, if the injection pressure reaches the pressure threshold for expansion of the elastic sheath, the elastic sheath expands elastically, opening the potential gap cavity and receiving at least a portion of the liquid delivered from the syringe, thereby reducing the injection pressure within the syringe. This prevents the substance within the syringe from exiting through the needle.

[0084] (3) When the needle tip extends and reaches the target location in the suprachoroidal space, the liquid in the needle automatically depressurizes and is injected into the suprachoroidal space. The injection pressure between the syringe and the needle decreases accordingly. The elastic sheath, which is in an expanded state, contracts in response to the decrease in injection pressure to maintain the injection pressure in the potential space cavity higher than the pressure in the suprachoroidal space. This allows at least a portion of the material in the potential space cavity to be delivered to the suprachoroidal space via the needle tip until the elastic sheath adheres to the conduit wall of the connector, closing the potential space cavity.

[0085] Optionally, the needle mainly includes a needle tube, a sleeve, an elastic element, and a needle hub, wherein the distal end of the needle hub is provided with a mounting part for mounting and fixing the needle tube and exposing the tip of the needle tube to the distal end face of the sleeve, and is fluidly connected to the needle tube via the needle hub through a syringe adapter;

[0086] The proximal end of the sleeve abuts against the elastic element, which in turn abuts against the needle hub. The elastic element can compress and deform by increasing the tissue back pressure at the target location, causing the sleeve to move toward the distal end of the syringe, thereby further extending the length of the needle tube protruding from the distal end face of the sleeve.

[0087] When the elastic sheath expands, the operator applies further force to the tissue contacted at the distal end of the sleeve through the needle hub, increasing the tissue back pressure of the target tissue, compressing the elastic element, and moving the sleeve toward the distal end of the syringe. This further extends the length of the needle tube protruding from the distal end face of the sleeve, reaching the suprachoroidal space at the target location.

[0088] In a third aspect, this application provides an injection assembly, including the aforementioned syringe adapter, wherein the chamber is provided with an air vent; a syringe with a through hole on its wall, the distal end of the syringe being connected to the syringe adapter; a housing sealed and fitted onto the syringe, the housing allowing air to circulate between the syringe and the chamber through the through hole and the air vent; a needle, the needle including a needle tube, a sleeve fitted onto the distal end of the connector, and a needle seat fitted within the chamber, the distal end of the conduit always remaining within the needle seat and in fluid connection with the needle tube; a piston assembly provided within the syringe, the piston assembly moving axially within the syringe, capable of compressing at least a portion of the air within the syringe, allowing at least a portion of the air within the syringe to enter the chamber, driving the needle seat to move within the sleeve.

[0089] Optionally, the injection component mainly includes:

[0090] A syringe adapter with air holes on the connecting chamber.

[0091] A syringe with a through hole in its barrel wall; the syringe mainly includes:

[0092] A housing that is sealed onto the syringe is configured to allow air to circulate between the syringe and the connecting chamber through a through hole in the syringe wall;

[0093] The plunger has its distal end inside the syringe and its proximal end outside the syringe. By applying force to the proximal end of the plunger, the substance inside the syringe is delivered to the needle.

[0094] And a piston assembly inside the syringe, which moves axially against the inner wall of the syringe under the action of the push rod, so that at least part of the air inside the syringe enters the connector chamber through the housing, and the air in the connector chamber is sufficient to generate enough air to move the needle seat fitted in the connector chamber toward the distal end of the sleeve of the needle, so that the needle tip can protrude from the distal end face of the sleeve.

[0095] The needle mainly includes a needle tube, a sleeve at the distal end of a connecting piece, and a needle seat inside the sleeve and fitted within the cavity of the connecting piece. The needle seat has a cavity configured to be fluid-sealed with the needle tube of the needle, so that the distal end of the catheter is always kept in the cavity of the needle seat and fluidly connected with the needle tube.

[0096] Specifically, when the proximal end of the plunger is subjected to force, the combined action of the syringe, syringe adapter, and needle results in:

[0097] Before the needle tip protrudes from the distal end of the sleeve, force is applied to the proximal part of the plunger to cause the piston assembly to move axially within the syringe wall, compressing the air inside the syringe. This air is then introduced through the through-hole into the cavity of the connector, making the air in the connector cavity sufficient to move the needle hub, which is fitted into the connector cavity, toward the distal end of the needle sleeve. The needle tip can then protrude from the distal end of the sleeve and be inserted into the eye tissue at the target location contacted by the distal end of the sleeve.

[0098] (1) When the needle tip is located in the suprachoroidal space at the target location, the injection pressure generated in the syringe is insufficient to cause the elastic sheath to expand and detach from the contact with the catheter wall, and at least a portion of the substance in the syringe is output through the needle.

[0099] (2) When the needle is located in the sclera at the target location, the injection pressure generated by the syringe is sufficient to cause the elastic sheath to expand and disengage from the connector conduit, open the potential gap cavity and receive at least a portion of the substance delivered from the syringe, prevent the needle from delivering liquid from the syringe, and further compress the air in the connector cavity, thereby generating pressure to push the needle hub along the conduit in the cavity toward the distal end of the needle, so that the needle tip extends further toward the suprachoroidal space at the target location, reaching the suprachoroidal space at the target location;

[0100] (3) When the needle tip extends from the sclera to the suprachoroidal space, at least a portion of the substance in the needle tip is released in the suprachoroidal space, thereby reducing the injection pressure in the syringe.

[0101] When the injection pressure in the syringe is insufficient to resist the elastic force of the elastic sheath, the elastic sheath elastically retracts and fits against the catheter wall of the connector, closing the potential gap cavity. This forces the substance in the potential gap cavity to enter the catheter through the through-channel provided in the connector catheter and be delivered to the suprachoroidal space via the needle.

[0102] Optionally, as the elastic sheath retracts to drain the liquid in the potential cavity into the catheter, the elastic sheath of the traction component syringe adapter moves toward the catheter under the action of the traction component, guiding the distal end of the traction component to drive the needle hub to move along the catheter axis toward the distal end of the sleeve within the cavity, so that the needle tip located in the suprachoroidal cavity gradually retracts along the needle path formed by the needle in the scleral tissue at the target location.

[0103] Optionally, as the elastic sheath retracts to drain the liquid in the potential gap cavity into the catheter, the flexible bottom recovers its contraction under the action of the elastic sheath, causing the needle hub to move towards the connector, so that the needle tip gradually retracts along the needle path formed by the needle tube in the scleral tissue at the target location.

[0104] Optionally, the piston assembly mainly includes a first piston that contacts the distal end of the push rod and a second piston that contacts the substance. The compressed air formed in the syringe chamber between the first piston and the second piston is sufficient to cause the air pressure in the chamber of the connector to push the needle seat to move, causing the tip of the needle tube to move toward the distal end of the sleeve and insert into the eye tissue at the target location, but is insufficient to push the second piston to move toward the distal end of the syringe to increase the injection pressure in the syringe.

[0105] Optionally, the needle mainly includes a needle tube, a sleeve, and a needle hub housed within the sleeve, wherein:

[0106] The needle hub has a cavity, which is configured to be fluid-sealed with the catheter and to allow the catheter to slide axially within the cavity. The cavity is configured to be fluid-sealed with the needle tube of the needle, so that the catheter is fluidly connected with the needle tube of the needle within the cavity.

[0107] The proximal end of the sleeve is connected to the distal end of the syringe adapter connector. The needle seat is fitted inside the sleeve and abuts against the inner wall of the sleeve. An air bladder is provided between the proximal end of the sleeve and the needle seat. A through hole is provided on the sleeve wall at the proximal end of the sleeve to allow air to circulate between the housing and the air bladder. An air hole is provided at the distal end of the syringe adapter connector to allow air to circulate between the chamber of the syringe adapter connector and the air bladder of the sleeve.

[0108] The proximal end of the plunger is subjected to force, which, in conjunction with the syringe, syringe adapter, and needle, results in:

[0109] (1) When the needle tip does not contact the tissue surface at the target location, the force applied to the proximal part of the plunger is sufficient to cause the piston assembly to move axially on the inner wall of the syringe, compressing the air in the syringe, causing the air bladder in the sleeve to be introduced through the air housing in the syringe, driving the needle seat to move in the sleeve, causing the tip of the needle tube to move to the distal end of the sleeve, and inserting it into the tissue at the target location.

[0110] (2) When the needle tip is located in the suprachoroidal space at the target location, the injection pressure generated in the syringe is insufficient to cause the elastic sheath to expand and detach from the catheter wall, and at least a portion of the substance in the syringe is output through the needle.

[0111] (3) When the needle is located in the sclera at the target position, the injection pressure generated by the syringe is sufficient to cause the elastic sheath to expand and disengage from the connector conduit, open the potential gap cavity and receive at least a portion of the substance delivered from the syringe, so that the substance in the syringe cannot be output from the needle, and compressed air is generated in the cavity of the connector and enters the air bladder of the sleeve through the air hole provided at the distal end of the syringe adapter connector, causing the needle seat to move further to the distal end of the sleeve, driving the tip of the needle tube to extend towards the suprachoroidal space at the target position and reach the suprachoroidal space at the target position.

[0112] (4) When the needle tip extends from the sclera to the suprachoroidal space, at least a portion of the substance in the needle tip is released in the suprachoroidal space, thereby reducing the injection pressure in the syringe.

[0113] When the injection pressure inside the syringe is insufficient to resist the elastic force of the elastic sheath, the elastic sheath elastically retracts and fits against the tube wall of the connector, closing the potential gap cavity. This forces the liquid in the potential gap cavity to enter the syringe through the through-channel provided by the connector tube and then delivered to the suprachoroidal space via the needle.

[0114] Optionally, when the injection pressure inside the syringe is insufficient to resist the elastic force of the elastic sheath, the elastic sheath elastically retracts and fits against the tube wall of the connector. The chamber of the connector draws air from the air bag through the air hole provided at the distal end of the syringe adapter connector. The proximal end face of the needle hub moves and fits against the distal end of the syringe adapter connector, so that the needle tip gradually retracts along the needle path of the eye tissue at the target location to the sclera.

[0115] In this process, the retraction of the balloon causes the needle tip to retract along the needle path formed within the scleral tissue at the target location, while simultaneously delivering liquid from the syringe through the needle into the suprachoroidal space. This not only further increases the diffusion area of ​​the delivered liquid into the suprachoroidal space but also makes the intraocular pressure more stable during the liquid delivery process.

[0116] Optionally, the air volume in the inner chamber of the connector, after being expanded and compressed by the elastic sheath, is sufficient for the tip of the needle to extend towards the suprachoroidal space at the target location and reach the suprachoroidal space at the target location.

[0117] Optionally, the airbag mainly includes a body and an inflation mechanism on the body. The inflation mechanism allows air to circulate between the airbag and the shell through a through hole, and allows air to circulate between the airbag and the chamber of the syringe adapter connector through an air hole.

[0118] Optionally, the airbag can also be a sealed cavity formed by the needle seat, the sleeve wall and the distal end face of the connector, the sealed cavity being in communication with the housing through a through hole and with the chamber of the connector through an air hole.

[0119] Optionally, the syringe is provided with a push rod for driving the piston assembly to move; the piston assembly includes a first piston and a second piston that are separately disposed from each other, the first piston contacts the push rod, the first piston is used to compress at least a portion of the air in the syringe, so that at least a portion of the air in the syringe enters the chamber, thereby driving the needle seat to move within the sleeve; the second piston is stationary before the first piston contacts the second piston.

[0120] Optionally, the piston assembly mainly includes a first piston that contacts the distal end of the push rod and a second piston that contacts the liquid. The compressed air formed in the syringe chamber between the first piston and the second piston is sufficient to cause the air pressure in the second chamber of the connector to push the needle seat to move, so that the tip of the needle tube moves toward the distal end of the sleeve and is inserted into the tissue at the target position, but is insufficient to push the second piston to move toward the distal end of the syringe to increase the hydraulic pressure in the syringe.

[0121] Optionally, when the needle tip is located within the sclera, the first piston can block the through hole.

[0122] Optionally, when the needle is located in the sclera at the target position, the first piston can block the through hole provided on the syringe wall to ensure the airtightness of the airbag and prevent the airbag from depressurizing through the through hole provided on the syringe wall, thus affecting the movement of the tip of the needle from the sclera to the suprachoroidal space.

[0123] Optionally, the inner wall of the syringe is provided with an anti-retraction part, which contacts the first piston when it blocks the through hole. The anti-retraction part is used to ensure that the first piston in contact with it can only move in the syringe in the direction toward the distal end of the syringe.

[0124] Optionally, an anti-retraction part is provided in the periphery of the through hole on the syringe wall. However, when the anti-retraction part contacts the first piston and blocks the through hole on the syringe wall, the first piston can only move in the direction towards the syringe outlet end, and cannot move in the direction away from the outlet end. This prevents the first piston from moving in the direction away from the outlet end, causing the opening of the through hole to cause the gap cavity between the sleeve and the needle seat to depressurize, thereby affecting the gap cavity between the sleeve and the needle seat and pushing the needle seat to move towards the distal end of the sleeve.

[0125] Optionally, the anti-retraction part is a protrusion provided in the periphery of the through hole provided on the syringe wall, which protrudes in the direction of movement of the first piston toward the syringe outlet end.

[0126] Optionally, the anti-retraction part is an elastic retaining tooth provided in the periphery of the through hole provided on the syringe wall, which protrudes in the direction of movement of the first piston toward the syringe outlet end.

[0127] Optionally, the syringe is provided with a plunger for moving the piston assembly; a flexible bottom is provided at the distal end of the connector; and / or a fluid-sealed cavity is provided between the connector and the needle; and / or a traction component is provided in the region of the cavity and the chamber.

[0128] When the needle tip is not in contact with the eye tissue, the push rod can drive the piston assembly to move within the syringe, allowing at least a portion of the air in the syringe to enter the housing and the second chamber through the through hole, driving the needle hub to move within the sleeve, and causing the needle tip to move towards the distal end of the sleeve, thus inserting the needle tip into the eye tissue; when the needle tip is located within the sclera, the injection pressure generated by the syringe causes the elastic sheath to expand, compressing the air within the syringe adapter, pushing the needle hub towards the distal end of the needle, and causing the needle tip to extend into the suprachoroidal space; when the needle tip is located in the suprachoroidal space and releases at least a portion of the substance, the elastic sheath elastically retracts, and the flexible bottom, or the cavity, or any one of the traction components causes the needle hub to move towards the distal end of the connector, causing the needle tip to retract.

[0129] In a fourth aspect, this application provides an injection assembly, including the aforementioned syringe adapter, a syringe, wherein the syringe barrel has a through hole and the distal end of the syringe is connected to the syringe adapter; a needle, the needle being connected to the distal end of the syringe adapter; the needle including a needle tube, a sleeve, an air bladder, and a needle hub, the proximal end of the sleeve being connected to the distal end of the connector; a housing, the housing being fitted onto the syringe adapter, wherein a through hole is provided on the barrel wall of the proximal end of the sleeve to allow air to circulate between the housing and the air bladder, and the housing allowing air to circulate between the syringe and the air bladder through the through hole and the through hole; a piston assembly is provided inside the syringe, the piston assembly being capable of compressing at least a portion of the air inside the syringe, causing at least a portion of the air inside the syringe to enter the air bladder, driving the needle hub to move within the sleeve.

[0130] Optionally, the syringe is equipped with a push rod for moving the piston assembly. When the needle tip of the syringe is not in contact with the eye tissue, the push rod can move the piston assembly within the syringe, allowing at least a portion of the air in the syringe to enter the air bladder through the through-hole, thereby driving the needle hub to move within the sleeve, causing the needle tip to move towards the distal end of the sleeve, thus inserting the needle tip into the eye tissue. When the needle tip is located within the sclera, the elastic sheath expands, compressing the space of the second chamber, allowing at least a portion of the air in the second chamber to enter the air bladder, causing the needle hub to move further towards the distal end of the sleeve, thus extending the needle tip towards the suprachoroidal space. When the needle tip is located in the suprachoroidal space, the elastic sheath elastically retracts, the second chamber draws air from the air bladder, and the needle hub moves towards the distal end of the connector, causing the needle tip to retract.

[0131] Optionally, the distal end of the sleeve is provided with a clamping port for pressing eye tissue.

[0132] Optionally, the clamping port has an annular end face with a minimum inner diameter of 1mm-3mm. During use, the needle is inserted into the injection point for injection. The minimum inner diameter of the annular end face of the clamping port refers to the length of the shortest line segment passing through the injection point with both ends located inside the clamping port, and the injection point is located at the center of this line segment. Experimental results show that when the minimum inner diameter is 1-3mm, the area of ​​ocular tissue within the clamping port is moderate, and a noticeable protrusion can be formed within the clamping port, facilitating injection. The clamping port facilitates contact with ocular tissue and fixes the position of the syringe, improving the success rate of injection and allowing the drug solution to be smoothly delivered to the target site.

[0133] Optionally, the distal end of the sleeve and / or the distal end of the needle hub is formed into a protruding structure, the protruding structure being used to form a concave region in the ocular tissue that contacts the sleeve and / or the needle hub.

[0134] Optionally, the proximal end of the syringe also features a limiting structure for securing the operator's fingers. This limiting structure can be a protrusion, a notch, or a ring. Ophthalmic syringes typically have an outer diameter of a few millimeters, requiring the operator to wear gloves to directly handle the syringe. However, rubber gloves are inconvenient for manipulating the syringe casing, often resulting in unstable grip and slippage. The limiting structure facilitates finger positioning, allowing the operator to easily hold the syringe sleeve and simplifying operation.

[0135] Optionally, a seal is provided between the syringe and the syringe adapter, and / or between the syringe adapter and the needle.

[0136] When a seal is provided between the syringe outlet end (i.e., the distal tightening part of the syringe) and the syringe adapter, the seal is fitted onto the proximal end of the syringe adapter (i.e., the proximal end of the connector). When the syringe outlet end and the connector of the syringe adapter are abutted together, the seal fits against the proximal end of the syringe adapter to prevent pressure leakage inside the syringe, thereby affecting the accuracy of quickly judging whether the needle tip is in the suprachoroidal space of the target position.

[0137] When a sealing member is provided between the distal end of the syringe adapter connector and the needle hub, and the sealing member is fitted onto the proximal end of the needle hub, when the syringe adapter and the needle hub connector are connected, the sealing member fits against the proximal end of the needle hub, preventing pressure leakage in the air bladder, thereby affecting the needle hub from moving further to the distal end of the sleeve, making it difficult for the tip of the needle tube to extend to the target location in the suprachoroidal space.

[0138] The “sealant” or “sealing component” mentioned in this application refers to the material or part of a component that prevents gas or fluid from leaking between adjacent mating surfaces.

[0139] Optionally, the exposed length of the needle tip is 500-2000 micrometers, preferably 700-1350 micrometers, and more preferably 700-1100 micrometers.

[0140] Optionally, the length of the cutting edge of the needle tip is less than or equal to 1100 micrometers, preferably less than or equal to 900 micrometers, more preferably less than or equal to 700 micrometers, more preferably less than or equal to 550 micrometers, and most preferably 250-550 micrometers.

[0141] Optionally, the needle tip extending from the sclera into the suprachoroidal space has a length of approximately 1000 micrometers or less, approximately 800 micrometers or less, approximately 600 micrometers or less, approximately 400 micrometers or less, approximately 200 micrometers or less, approximately 100 micrometers or less, approximately 80 micrometers or less, approximately 50 micrometers or less, approximately 30 micrometers or less, approximately 20 micrometers or less, or approximately 10 micrometers or less. In some embodiments, the needle tip extending from the sclera into the suprachoroidal space has a length of approximately 1000 micrometers. In other embodiments, the needle tip extending from the sclera into the suprachoroidal space has a length of approximately 800 micrometers, or approximately 600 micrometers, or approximately 400 micrometers, or approximately 200 micrometers, or approximately 100 micrometers, or approximately 80 micrometers, or approximately 50 micrometers, or approximately 30 micrometers, or approximately 20 micrometers, or approximately 10 micrometers.

[0142] Optionally, the liquid capacity of the potential gap cavity is approximately 1000 μL or less, approximately 800 μL or less, approximately 500 μL or less, approximately 300 μL or less, approximately 200 μL or less, approximately 100 μL or less, approximately 80 μL or less, approximately 50 μL or less, approximately 30 μL or less, approximately 25 μL or less, or approximately 15 μL. In some embodiments, the liquid capacity of the potential gap cavity may be approximately 1000 μL. In other embodiments, the liquid capacity of the potential gap cavity may be approximately 800 μL, or approximately 500 μL, or approximately 300 μL, or approximately 300 μL, or approximately 100 μL, or approximately 80 μL, or approximately 50 μL, or approximately 35 μL, or approximately 25 μL, or approximately 15 μL.

[0143] In a fifth aspect, this application provides a method of using a syringe adapter, for use with the aforementioned syringe adapter, comprising the following steps:

[0144] S1. The proximal end of the connector is abutted against the distal end of the syringe, the syringe including a plunger capable of moving a substance within the syringe; the distal end of the connector is abutted against the needle, the needle including a needle tip, the needle tip serving as the delivery outlet for the substance within the syringe; thus achieving fluid connection between the syringe adapter, the syringe, and the needle.

[0145] S2. When the needle comes into contact with the eye tissue, force is applied to the push rod:

[0146] When the needle tip is located in the suprachoroidal space, the injection pressure generated in the syringe is insufficient to cause the elastic sheath to expand and disengage from the catheter wall, the elastic sheath is in the first configuration, and at least a portion of the substance in the syringe;

[0147] When the needle tip is located within the sclera, the injection pressure generated within the syringe is sufficient to cause the elastic sheath to expand and detach from the catheter wall, the elastic sheath changes from a first configuration to a second configuration, and at least a portion of the substance delivered by the syringe is discharged into the potential gap cavity through the through-channel, and the substance within the syringe cannot be output from the needle tip;

[0148] S3. When the elastic sheath is found to be inflated, further force is applied directly or indirectly to the needle, and the eye tissue in contact with the needle is further compressed, so that the needle tip extends from the sclera to the suprachoroidal space.

[0149] S4. When the needle tip extends from the sclera to the suprachoroidal space, at least a portion of the substance in the needle tip is released, thereby reducing the injection pressure in the syringe;

[0150] S5. When the injection pressure in the syringe decreases to a level insufficient to resist the elastic force of the elastic sheath, the elastic sheath elastically retracts and adheres to the catheter wall, the elastic sheath changes from the second configuration to the first configuration, forcing at least a portion of the material in the potential gap cavity to be discharged into the catheter through the through-channel and delivered to the suprachoroidal space through the needle, until the elastic sheath adheres to the catheter wall of the connector and closes the potential gap cavity.

[0151] This syringe adapter allows the use of a conventional syringe. By fixing the syringe adapter to the distal end of the syringe, the syringe and needle are combined. It not only allows for a more intuitive assessment of whether the needle has penetrated the sclera and reached the suprachoroidal space by observing changes in the volume of the cavity within the syringe adapter or the expansion of the elastic sheath, thus guiding the doctor in drug injection, but also opens the potential cavity when the needle tip is located within the sclera at the target location. This allows for the reception of at least a portion of the liquid delivered from the syringe to balance the hydraulic pressure within the syringe, preventing leakage of the liquid from the syringe through the needle insertion site in the sclera due to the hydraulic pressure exceeding the tissue back pressure of the sclera, which could lead to reflux or subconjunctival spread.

[0152] When the operator notices that the elastic sheath of the syringe adapter of this application expands or the volume of the potential gap cavity within the syringe adapter increases, it can be determined that the needle tip is located in the sclera at the target location rather than in the suprachoroidal space at the target location. The operator can apply force to the needle using the syringe, plunger, or other components to further compress the tissue in the area that contacts the distal end of the sleeve at the target location, thereby shortening the distance the needle tip travels from the surface of the tissue in the target location area into the suprachoroidal space, so that the needle tip can extend from the sclera to the suprachoroidal space.

[0153] When the needle tip extends from the sclera to the suprachoroidal space, the fluid inside the needle tip is released because the tissue density of the suprachoroidal space is lower than that of the sclera, thus reducing the injection pressure in the syringe.

[0154] When the injection pressure in the syringe is insufficient to resist the elastic force of the elastic sheath, the elastic sheath elastically retracts and fits against the catheter wall of the connector, closing the potential gap cavity. This forces the liquid in the potential gap cavity to enter the catheter through the perforation channel and be delivered to the suprachoroidal space via the needle.

[0155] In a sixth aspect, this application provides a method of using a syringe adapter, for use with the aforementioned syringe adapter, comprising the following steps:

[0156] S1. The proximal end of the connector is abutted against the distal end of the syringe, the syringe including a plunger capable of moving liquid within the syringe;

[0157] The distal end of the connector is abutted against and connected to the needle, the needle including a needle tip, the needle tip serving as the delivery outlet for the substance inside the syringe;

[0158] This enables fluid connection between the syringe adapter, the syringe, and the needle;

[0159] S2. When the distal surface of the needle contacts the ocular tissue, a force is applied to the push rod such that:

[0160] When the needle tip is located in the suprachoroidal space, if the injection pressure between the syringe and the needle exceeds the pressure threshold for expansion of the elastic sheath, the elastic sheath expands, changing from a first configuration to a second configuration, opening a potential gap cavity to receive at least a portion of the substance delivered from the syringe, and reducing the injection pressure. This allows for effective control of the release rate of the substance within the syringe in the suprachoroidal space, preventing excessively rapid release or sudden release.

[0161] When the needle tip is located in the suprachoroidal space, if the injection pressure between the syringe and the needle is lower than the pressure threshold for the expansion of the elastic sheath, the elastic sheath is in a first configuration, closing the potential gap cavity, and at least a portion of the substance in the syringe is output through the needle.

[0162] When the needle tip is located within the sclera, if the injection pressure between the syringe and the needle is higher than the pressure threshold for the expansion of the elastic sheath, the elastic sheath expands, changing from a first configuration to a second configuration, opening a potential gap cavity to receive at least a portion of the substance delivered from the syringe, reducing the injection pressure so that the substance in the syringe cannot be output from the needle.

[0163] As the needle tip extends from the sclera into the suprachoroidal space and delivers substance, the injection pressure between the syringe and the needle decreases, and the elastic sheath contracts, changing from a second configuration to a first configuration to maintain an injection pressure between the syringe and the needle that is higher than the pressure within the suprachoroidal space. This allows at least a portion of the substance within the potential space to be delivered to the suprachoroidal space via the needle tip until the elastic sheath closes the potential space.

[0164] In a seventh aspect, this application provides a method of using a syringe adapter, for use with the aforementioned syringe adapter, comprising the following steps:

[0165] S1. The proximal end of the connector is abutted against the distal end of the syringe, the syringe including a push rod capable of moving the substance inside the syringe; the distal end of the connector is abutted against the needle, the needle including a needle tip, the needle tip serving as the delivery outlet for the substance inside the syringe; thus achieving fluid connection between the syringe adapter, the syringe, and the needle.

[0166] S2. When the needle contacts the eye tissue, a force is applied to the push rod, such that:

[0167] When the needle tip is located in the suprachoroidal space, the injection pressure generated in the syringe is insufficient to cause the elastic sheath to expand and disengage from the catheter wall. The elastic sheath is in the first configuration, and at least a portion of the substance in the syringe is output through the needle.

[0168] When the needle tip is located within the sclera, the injection pressure generated within the syringe is sufficient to cause the elastic sheath to expand and detach from the catheter wall, the elastic sheath changes from a first configuration to a second configuration, and at least a portion of the substance delivered by the syringe is discharged into the potential gap cavity through the through-channel, and the substance within the syringe cannot be output from the needle.

[0169] When the elastic sheath changes from the first configuration to the second configuration, that is, when the elastic sheath expands and disengages from the catheter wall, at least part of the liquid in the chamber is pressurized to form high-pressure liquid and squeezes the flexible bottom and / or the traction component, causing the needle hub to move toward the distal end of the connector, thereby driving the needle tip to extend further into the suprachoroidal space.

[0170] S3. When the needle tip extends and reaches the suprachoroidal space, the liquid in the needle tip is released, reducing the injection pressure in the syringe. The elastic sheath changes from the second configuration to the first configuration. The liquid in the potential gap cavity is discharged into the catheter through the through-channel and delivered to the suprachoroidal space via the needle tip.

[0171] When the elastic sheath changes from the second configuration to the first configuration, the pressure of at least part of the liquid in the chamber decreases to an insufficient level to resist the elastic force of the flexible bottom. The flexible bottom and / or the traction component then retract, causing the needle tip to gradually retract.

[0172] In a seventh aspect, this application provides a method of using an injection component, which employs the aforementioned syringe adapter, and the specific method of use includes the following steps:

[0173] (1) Place the distal end of the plunger inside the syringe. When the needle contacts the eye tissue at the target location, the operator applies force to the proximal end of the plunger that is exposed in the syringe. With the combined action of the syringe, syringe adapter, and needle, the following occurs:

[0174] When the needle tip is located in the suprachoroidal space at the target location, the injection pressure generated in the syringe is insufficient to cause the elastic sheath to expand and detach from the catheter wall, and at least a portion of the liquid in the syringe is output through the needle.

[0175] When the needle tip is located in the sclera at the target location, the injection pressure generated in the syringe is sufficient to cause the elastic sheath to expand and disengage from the catheter wall, opening the potential gap cavity and receiving at least a portion of the liquid delivered from the syringe through the through channel of the connector catheter, so that the liquid in the syringe cannot be output from the needle.

[0176] (2) The operator applies force to the needle by using a syringe, plunger or other components to further compress the tissue in the area that contacts the distal end of the sleeve at the target location, thereby shortening the distance the needle tip travels from the surface of the tissue in the target location area into the suprachoroidal space, so that the needle tip can extend from the sclera to the suprachoroidal space.

[0177] When the needle tip extends from the sclera to the suprachoroidal space, the liquid in the needle tip is released in the suprachoroidal space, reducing the injection pressure in the syringe.

[0178] When the injection pressure in the syringe decreases to a level insufficient to resist the elastic force of the elastic sheath, the elastic sheath retracts elastically and adheres to the catheter wall of the connector, closing the potential gap cavity. This forces the liquid in the potential gap cavity to enter the catheter through the perforation channel and be delivered to the suprachoroidal space via the needle.

[0179] In an eighth aspect, this application provides a method of using an injection component, which employs the aforementioned syringe adapter, and the method of use includes the following steps:

[0180] Place the distal end of the plunger inside the syringe. When the needle contacts the target eye tissue, the operator applies force to the proximal end of the plunger, which protrudes from the syringe. With the combined action of the syringe, syringe adapter, and needle, the following occurs:

[0181] When the needle tip is located in the suprachoroidal space at the target location, the elastic sheath is in the first configuration, the elastic sheath fits against the catheter wall, the first chamber of the connector chamber is closed, and at least a portion of the liquid is delivered from the syringe through the needle.

[0182] When the needle tip is located in the sclera at the target location, the elastic sheath expands under the injection pressure in the syringe and disengages from the catheter wall. When the elastic sheath changes to the second configuration, the first chamber is opened and receives at least a portion of the liquid in the syringe.

[0183] The increased air pressure in the second chamber causes the needle seat, which is fitted in the connecting chamber, to move towards the distal end of the sleeve, allowing the needle tip to extend further into the suprachoroidal space at the target location.

[0184] As the needle tip extends and reaches the suprachoroidal cavity at the target location, the second configuration of the elastic sheath transforms into the first configuration, closing the first chamber space of the connector, allowing the liquid inside the first chamber to flow out and be delivered to the suprachoroidal cavity via the needle.

[0185] As the second configuration of the elastic sheath transforms into the first configuration, the syringe adapter, under the action of the elastic sheath, drives the needle hub to move towards the connector, causing the needle tip to gradually retract along the needle path formed by the needle tube within the scleral tissue at the target location.

[0186] Optionally, it also includes:

[0187] Place the distal end of the plunger inside the syringe. When the needle contacts the target eye tissue, the operator applies force to the proximal end of the plunger, which protrudes from the syringe. This, combined with the syringe, syringe adapter, and needle, causes:

[0188] When the needle tip is located within the sclera at the target location, the elastic sheath expands under the hydraulic pressure of the syringe. The operator applies force to the needle tip through the syringe, plunger, or other components, causing the distal end of the sheath to press further against the ocular tissue in contact with the distal end of the sheath via the needle hub. The increased back pressure on the pressed ocular tissue forces the elastic element to be compressed, causing the sheath to move towards the distal end of the syringe. This further extends the length of the needle protruding from the distal end face of the sheath, reaching the suprachoroidal space at the target location.

[0189] Optionally, it also includes:

[0190] Place the distal end of the plunger inside the syringe. When the needle sheath contacts the target ocular tissue, the operator applies force to the proximal end of the plunger, which protrudes from the syringe. This, combined with the syringe, syringe adapter, and needle, causes:

[0191] (1) When the needle tip does not contact the tissue surface at the target location, the force applied to the proximal part of the plunger is sufficient to cause the piston assembly to move axially on the inner wall of the syringe, compressing the air in the syringe, causing the air bladder in the sleeve to be introduced through the air housing in the syringe, driving the needle seat to move in the sleeve, causing the tip of the needle tube to move to the distal end of the sleeve, and inserting it into the tissue at the target location.

[0192] (2) When the needle tip is located in the suprachoroidal space at the target location, the injection pressure generated in the syringe is insufficient to cause the elastic sheath to expand and detach from the catheter wall, and at least a portion of the liquid in the syringe is output through the needle.

[0193] (3) When the needle is located in the sclera at the target location, the injection pressure generated by the syringe is sufficient to cause the elastic sheath to expand and disengage from the connector conduit, opening the potential gap cavity and receiving at least a portion of the liquid delivered from the syringe, preventing the needle from delivering liquid from the syringe, and generating compressed air in the chamber of the connector, which enters the potential gap cavity through the air hole provided at the distal end of the syringe adapter connector, causing the needle seat to move further towards the distal end of the sleeve, driving the tip of the needle tube to extend towards the first area of ​​the target location, reaching the suprachoroidal space at the target location.

[0194] (4) When the needle tip extends from the sclera to the suprachoroidal space, the liquid in the needle tip is released in the suprachoroidal space, which reduces the injection pressure in the syringe.

[0195] When the injection pressure in the syringe is insufficient to resist the elastic force of the elastic sheath, the elastic sheath elastically retracts and fits against the catheter wall of the connector, closing the potential gap cavity, forcing the liquid in the potential gap cavity to enter the catheter through the through-channel and be delivered to the suprachoroidal space through the needle.

[0196] (5) As the elastic sheath elastically retracts and fits against the catheter wall of the connector, closing the potential gap cavity, the chamber of the connector draws air from the air bag through the air hole provided at the distal end of the syringe adapter connector. The proximal end of the needle seat moves towards the distal end of the syringe adapter connector and fits against it, so that the needle tip gradually retracts along the needle path of the eye tissue at the target position to the sclera.

[0197] Optionally, the proximal portion of the plunger is subjected to force, which, in conjunction with the syringe, syringe adapter, and needle, causes:

[0198] (1) When the needle tip does not contact the tissue surface at the target location, the proximal part of the push rod is subjected to force, causing the piston assembly to move axially within the syringe and generate compressed air that is introduced into the sleeve through the housing. This causes the air bladder to expand and move the needle hub towards the distal end of the sleeve within the sleeve. The needle tip then protrudes from the distal end of the sleeve and is inserted into the tissue at the target location.

[0199] (2) When the needle tip is located in the suprachoroidal space at the target location, the injection pressure generated in the syringe is insufficient to cause the elastic sheath to expand and detach from the contact with the catheter wall, and at least a portion of the liquid is delivered from the syringe through the needle.

[0200] (3) When the needle is located in the sclera at the target position, the injection pressure generated by the syringe is sufficient to expand the elastic sheath to open the potential gap cavity and receive at least a portion of the liquid delivered from the syringe, so that the liquid in the syringe cannot be output from the needle, and the air outside the elastic sheath in the chamber of the connector is compressed and enters the air bladder through the air hole provided at the distal end of the connector, causing the air bladder to expand further, driving the needle seat to move further to the distal end of the sleeve, and driving the needle tip to extend to the suprachoroidal cavity at the target position, reaching the suprachoroidal cavity at the target position.

[0201] (4) When the needle tip extends from the sclera to the suprachoroidal space, the liquid in the needle tip is released in the suprachoroidal space, which reduces the injection pressure in the syringe.

[0202] (5) When the injection pressure in the syringe is insufficient to resist the elastic force of the elastic sheath, the elastic sheath elastically retracts and fits against the catheter wall of the connector, closing the potential gap cavity, forcing the liquid in the potential gap cavity to enter the catheter through the through channel and be delivered to the suprachoroidal space through the needle.

[0203] (6) When the elastic sheath retracts elastically and moves to fit against the conduit wall of the connector, the second chamber of the connector draws air from the air bladder through the air hole provided at the distal end of the connector. The air bladder contracts, causing the proximal end of the needle seat to move towards the distal end of the connector and fit against it, so that the needle tip gradually retracts along the needle path of the eye tissue at the target position to the sclera.

[0204] Ninthly, this application provides a kit comprising: a vial containing a drug solution; and an injection assembly; wherein the injection assembly employs the aforementioned syringe adapter and needle. This kit connects the syringe and needle together via the syringe adapter, allowing for a more direct assessment of whether the needle tip has penetrated the sclera to reach the suprachoroidal space by monitoring changes in the volume of the cavity within the syringe adapter or the expansion of the elastic sheath, thus guiding the physician in drug injection. Furthermore, by adjusting the injection pressure between the syringe and the needle, the release rate of the drug solution within the suprachoroidal space can be effectively controlled, preventing excessively rapid or sudden release.

[0205] Optionally, the drug solution contains one or more drug solutions with active pharmaceutical ingredients, wherein the active pharmaceutical ingredients may be selected from antibodies, antiviral agents, chemotherapeutic agents, analgesics, anesthetics, aptamers, antihistamines, anti-inflammatory agents, and antitumor agents.

[0206] Optionally, the vial contains one or more gene therapy drugs using recombinant adeno-associated virus (rAAV) as a vector, wherein the AAV is selected from AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10, or mutants thereof; preferably, the AAV is AAV8 or a mutant thereof. The rAAV preferably contains drugs expressing the therapeutic properties of ocular diseases, such as anti-VEGF drugs, complement factor inhibitors (complement component C3, complement factor B, complement factor D), plasma kallikrein inhibitors, PDGFR inhibitors, tyrosine kinase inhibitors, integrin inhibitors, angiopoietin-2 inhibitors, and Tie-2 agonists.

[0207] Tenthly, this application provides a reagent kit, comprising: a pre-filled injection assembly; the pre-filled injection assembly employs the aforementioned syringe adapter, pre-filled syringe, and needle. The syringe adapter connects the pre-filled syringe and needle together. It not only allows for a more direct assessment of whether the needle has penetrated the sclera to reach the suprachoroidal space by observing changes in the volume of the cavity within the syringe adapter or the expansion of the elastic sheath, thus guiding the physician in drug injection, but also allows for effective control of the release rate of the substance in the suprachoroidal space by adjusting the injection pressure between the syringe and the needle, preventing excessively rapid injection or sudden release. The syringe adapter described in this application, when combined with existing pre-filled syringes, not only allows for a more direct assessment of whether the needle has penetrated the sclera to reach the suprachoroidal space, guiding the physician in drug injection, reducing drug residue, ensuring more accurate dosage, preventing injury to staff during drug preparation or inaccurate dosage, and reducing the probability of drug use errors and the risk of cross-contamination, but also allows for effective control of the release rate of the drug solution in the suprachoroidal space by adjusting the injection pressure between the syringe and the needle, preventing excessively rapid injection or sudden release.

[0208] Optionally, the pre-filled syringe is pre-filled with a drug solution containing one or more drug-active liquids, wherein the drug-active liquids may be selected from antibodies, antiviral agents, chemotherapeutic agents, analgesics, anesthetics, aptamers, antihistamines, anti-inflammatory agents, and antitumor agents.

[0209] Optionally, the pre-filled syringe described in this application is pre-filled with one or more gene therapy drugs using recombinant adeno-associated virus (rAAV) as a vector, wherein the AAV is selected from AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10 or their mutants; preferably, the AAV is AAV8 or its mutants. The rAAV preferably contains drugs expressing the therapeutic properties of ocular diseases, such as anti-VEGF drugs, complement factor inhibitors (complement component C3, complement factor B, complement factor D), plasma kallikrein inhibitors, PDGFR inhibitors, tyrosine kinase inhibitors, integrin inhibitors, angiopoietin-2 inhibitors, and Tie-2 agonists.

[0210] The drug solution filling technology for pre-filled syringes described in this application is well known in the art.

[0211] Compared with the prior art, the beneficial effects of this application are as follows:

[0212] 1. The syringe adapter provided in this application utilizes the structure of existing syringes to combine the syringe and needle together. The operator can more intuitively judge whether the needle has penetrated the sclera to reach the suprachoroidal space by the change in the volume of the potential interstitial cavity or the expansion of the elastic sheath, so as to guide the operator to inject drugs and significantly improve the convenience of the operator's injection.

[0213] 2. The syringe adapter provided in this application utilizes the structure of an existing syringe. When the needle tip is located in the suprachoroidal space at the target position, the potential gap cavity is hydraulically opened to receive at least a portion of the liquid delivered from the syringe to balance the hydraulic pressure within the syringe. This prevents the needle from delivering liquid from the syringe, effectively avoiding leakage of liquid from the syringe through the needle insertion site in the sclera due to the hydraulic pressure exceeding the tissue back pressure of the sclera, which could lead to reflux or subconjunctival spread. Simultaneously, when the needle tip extends further from the sclera into the suprachoroidal space, the liquid within the needle tip is released, and the hydraulic pressure within the syringe closes the potential gap cavity. This allows the liquid within the potential gap cavity to be completely drained into the syringe and delivered to the suprachoroidal space via the needle, effectively ensuring the accuracy of the suprachoroidal space drug delivery dosage.

[0214] 3. The syringe adapter provided in this application utilizes the structure of existing syringes and adjusts the injection pressure between the syringe and the needle to effectively control the release rate of liquid in the suprachoroidal space, thereby avoiding a series of risks caused by excessively rapid injection or sudden drug release.

[0215] 4. The injection assembly provided in this application has an elastic element at the proximal end of the sleeve of the needle, and the proximal end of the sleeve abuts against the distal end of the elastic element. When the elastic sheath expands, the operator applies further force to the tissue contacted by the distal end of the sleeve through the needle hub, which increases the tissue back pressure of the target tissue, compresses the elastic element, and moves the sleeve toward the distal end of the syringe, thereby further extending the length of the needle tube exposed above the distal end face of the sleeve and reaching the suprachoroidal space at the target location.

[0216] 5. The injection assembly provided in this application, through the interaction of the piston assembly configured in the syringe with the needle and the syringe adapter, utilizes the compressed air generated by the movement of the piston assembly in the syringe to enter the air bladder of the needle or the cavity in the syringe adapter through the housing, thereby driving the movable needle hub in the sleeve to move towards the distal end of the sleeve, so that the needle tip of the needle protrudes from the distal end of the sleeve and is inserted into the eye tissue from the target position.

[0217] 6. The injection assembly provided in this application uses an elastic sleeve to expand in the connecting chamber via a syringe adapter, thereby pressurizing the gas in the second chamber, which drives the movable needle hub in the sleeve to move further towards the distal end of the sleeve, causing the tip of the needle tube to extend towards the suprachoroidal space at the target location, reaching the suprachoroidal space at the target location.

[0218] The injection assembly provided in this application, in which the distal end of the needle tube is located in the suprachoroidal space for injection, when the adapter, in conjunction with the syringe and the needle, enables the needle tip to retract along the needle path formed in the scleral tissue at the target location during the injection process, not only allowing the liquid to diffuse further in the suprachoroidal space, but also making the intraocular pressure more stable during the liquid delivery process in the syringe. Attached Figure Description

[0219] To more clearly illustrate the technical solutions of the embodiments of this application and the prior art, the drawings used in the embodiments and the prior art are briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0220] Figure 1A -B is a schematic diagram of the syringe adapter structure provided in Embodiment 1 of this application, wherein... Figure 1A This is an exploded view of the syringe adapter structure. Figure 1B Perspective view of the syringe adapter structure;

[0221] Figure 2 This is an exploded view of the assembly structure of the syringe adapter, conventional syringe, and needle according to Embodiment 1 of this application.

[0222] Figure 3 This is a schematic diagram of the syringe adapter of Embodiment 1 of this application, showing the needle tip located in the suprachoroidal space (wherein, the potential space chamber 16 is not shown);

[0223] Figure 4 This is a schematic diagram of the syringe adapter of Embodiment 1 of this application, in which the needle tip is located in the sclera under pressure and expands to open a potential gap cavity and receive the liquid in the syringe.

[0224] Figure 5 This is a schematic diagram of the state in which the needle tip extends into the suprachoroidal space to release liquid when the syringe adapter of Embodiment 1 of this application applies force to press the tissue in contact with the needle tip;

[0225] Figure 6This is a schematic diagram of the state in which the syringe adapter of Embodiment 1 of this application releases liquid by extending the needle tip into the suprachoroidal space, and the elastic sheath retracts to drain the liquid in the potential interstitial space into the catheter and deliver it to the suprachoroidal space.

[0226] Figure 7 A schematic diagram of the structure of the syringe adapter in Embodiment 3 of this application, showing a conspicuous layer provided on the outer wall of the elastic sheath;

[0227] Figure 8 A schematic diagram of a touch sensor is provided on the syringe adapter according to Embodiment 4 of this application. The touch sensor mainly includes a conductive layer, electrodes and a response mechanism.

[0228] Figure 9 A schematic diagram of a touch sensor is provided on the syringe adapter according to Embodiment 5 of this application. The touch sensor mainly includes an electrode layer, an electrode film, and a response mechanism.

[0229] Figure 10 This is an exploded view of the syringe adapter structure in Embodiment 6 of this application;

[0230] Figure 11 This is an exploded view of the assembly structure of the syringe adapter, conventional syringe, and needle in Embodiment 6 of this application.

[0231] Figure 12 This is a schematic diagram of the state in Embodiment 6 of this application, where the syringe adapter is the needle tip in the suprachoroidal space, and the elastic sheath is in the first configuration (the elastic sheath is not expanded and is in contact with the catheter wall).

[0232] Figure 13 This is a schematic diagram of Embodiment 6 of this application, showing the state in which the elastic sheath is in the second configuration (the elastic sheath expands and separates from the catheter wall) when the syringe adapter is the needle tip inside the scleral tissue, and the state in which no liquid is delivered to the needle tip.

[0233] Figure 14 This is a schematic diagram of the syringe adapter of Embodiment 6 of this application, in which the elastic sheath changes from the first configuration to the second configuration, and the needle tip extends to the suprachoroidal space to release liquid.

[0234] Figure 15 In the syringe adapter of Embodiment 6 of this application, the elastic sheath changes from the second configuration to the first configuration, draining the liquid from the first chamber and injecting it into the suprachoroidal cavity through the needle;

[0235] Figure 16 This is a schematic diagram showing the state in which the flexible bottom of the syringe adapter in Embodiment 6 of this application is connected to the needle hub, the elastic sheath changes from the second configuration to the first configuration, and the flexible bottom contracts, causing the needle tip to retract towards the sclera and release the liquid.

[0236] Figure 17 This is an exploded view of the syringe adapter in Embodiment 7 of this application;

[0237] Figure 18 This is an exploded view of the assembly structure of the syringe adapter, conventional syringe, and needle in Embodiment 7 of this application.

[0238] Figure 19 This is a schematic diagram of Embodiment 7 of this application, showing the release of liquid when the needle tip of the syringe adapter is in the suprachoroidal space.

[0239] Figure 20 This is a schematic diagram of Embodiment 7 of this application, showing that the syringe adapter is a needle tip that cannot release liquid when it is in the sclera;

[0240] Figure 21 This is a schematic diagram illustrating the expansion of the elastic sheath of the syringe adapter in Embodiment 7 of this application, which extends the needle tip into the suprachoroidal space to release liquid.

[0241] Figure 22 This is a schematic diagram illustrating how the elastic sheath of the syringe adapter in Embodiment 7 of this application contracts to expel liquid from the potential gap cavity and release it in the suprachoroidal space;

[0242] Figure 23 This is an exploded view of the syringe adapter structure of Embodiment 8 of this application;

[0243] Figure 24 This is an exploded view of the assembly structure of the syringe adapter, conventional syringe, and needle in Embodiment 8 of this application;

[0244] Figure 25 This is a schematic diagram of the syringe adapter in embodiment 8 of this application, showing the release of liquid when the needle tip of the needle is in the suprachoroidal space;

[0245] Figure 26 This is a schematic diagram of the syringe adapter in embodiment 8 of this application, where the needle tip cannot release liquid when it is in the sclera.

[0246] Figure 27 This is a schematic diagram illustrating the expansion of the elastic sheath of the syringe adapter in Embodiment 8 of this application, which extends the needle tip into the suprachoroidal space to release liquid.

[0247] Figure 28 This is a schematic diagram of the syringe adapter of Embodiment 8 of this application, showing the state in which the elastic sheath contracts and the needle tip retracts towards the sclera to release liquid.

[0248] Figure 29 This is a schematic diagram of the needle mounting elastic element of the injection assembly in Embodiment 13 of this application;

[0249] Figure 30 This is a schematic diagram of the injection assembly in Embodiment 13 of this application, where the elastic sheath expands when the needle tip is in the sclera, preventing the needle from releasing liquid.

[0250] Figure 31 This is a schematic diagram of the injection component of Embodiment 13 of this application, in which the needle tip extends into the suprachoroidal space under the action of an elastic element to complete the release of liquid.

[0251] Figure 32 In Embodiment 13 of this application, the injection component is a needle tip. Under the action of an elastic element, when the elastic sheath contracts, the liquid in the potential chamber is discharged into the needle through the catheter.

[0252] Figure 33 This is a schematic diagram of the syringe adapter structure with air holes in the injection assembly of Embodiment 14 of this application;

[0253] Figure 34 This is an exploded view of the structure of the injection assembly containing the piston assembly in Embodiment 14 of this application.

[0254] Figure 35 This is a schematic diagram showing the contact between the distal end of the sleeve (hidden and not shown) and the target tissue during insertion after the injection assembly of the injection component in Embodiment 14 is assembled and liquid is aspirated.

[0255] Figure 36 This is a schematic diagram of the injection assembly in Embodiment 14 where the piston assembly compresses the air inside the syringe under the action of the push rod to complete the needle insertion;

[0256] Figure 37 This is a schematic diagram of the injection assembly of Embodiment 14 of this application releasing liquid when the needle tip is in the suprachoroidal space;

[0257] Figure 38 This is a diagram showing the state where there is no liquid delivery at the needle tip of the injection component in Embodiment 14 of this application when the needle tip is inside the scleral tissue.

[0258] Figure 39 This is a schematic diagram of the elastic sheath of the injection assembly in Embodiment 14 of this application expanding to receive liquid in the syringe and extending the needle tip to release liquid in the suprachoroidal space.

[0259] Figure 40 As the elastic sheath of the injection assembly in Embodiment 14 of this application contracts, the needle tip retracts toward the sclera while draining the liquid in the potential interstitial cavity into the catheter and delivering it to the suprachoroidal space.

[0260] Figure 41 The syringe adapter of the injection assembly in Embodiment 14 of this application has a flexible bottom, and is shown in a schematic diagram of the state when the elastic sheath contracts and the needle tip retracts towards the sclera to release liquid.

[0261] Figure 42 The syringe adapter of the injection assembly in Embodiment 14 of this application is provided with a traction component, and is shown in a schematic diagram of the state when the elastic sheath contracts and the needle tip retracts towards the sclera to release the liquid.

[0262] Figure 43A -C is a schematic diagram of the syringe adapter and needle assembly and structure of the injection component in Embodiment 15 of this application, wherein... Figure 43A This is a schematic diagram of the assembly of a needle containing an air bladder and a syringe adapter. Figure 43B This is a schematic diagram showing the structure through which air from the syringe and the syringe adapter are introduced into the airbag via a through-hole and an air vent, respectively. Figure 43C A schematic diagram of a structure that introduces air from the syringe and syringe adapter into the air bladder solely through an air hole;

[0263] Figure 44A -B is an exploded view of the structure of the injection component containing the air bladder in Embodiment 15 of this application, wherein... Figure 44A This is a schematic diagram of the assembly and structure of an injection component that introduces air from the syringe and the syringe adapter into the airbag through a through-hole and an air vent, respectively. Figure 44B A schematic diagram of the assembly and structure of an injection assembly that introduces air from the syringe and the syringe adapter into the airbag only through an air hole;

[0264] Figure 45 This is a schematic diagram showing that when the injection component of Embodiment 15 of this application comes into contact with the eye tissue, the tip of the needle does not come into contact with the eye tissue;

[0265] Figure 46 This is a schematic diagram of the injection assembly in Embodiment 15 of this application, in which the piston assembly compresses the air inside the syringe under the action of the push rod to complete the needle insertion;

[0266] Figure 47 This is a schematic diagram of the injection assembly of Embodiment 15 of this application releasing liquid when the needle tip is in the suprachoroidal space;

[0267] Figure 48 This is a diagram showing the state where there is no liquid delivery at the needle tip of the injection component in Embodiment 15 of this application when the needle tip is inside the scleral tissue.

[0268] Figure 49 This is a schematic diagram of the elastic sheath of the injection assembly in Embodiment 15 of this application expanding to receive liquid in the syringe and extending the needle tip to release liquid in the suprachoroidal space.

[0269] Figure 50This is a schematic diagram showing the state when the elastic sheath of the injection assembly in Embodiment 15 of this application contracts, drains the liquid in the potential gap cavity into the catheter and delivers it to the suprachoroidal space, and when the elastic sheath contracts and the needle tip retracts towards the sclera to release the liquid.

[0270] Figure 51 This is a schematic diagram of the air bladder structure contained in the injection component of Embodiment 15 of this application;

[0271] Figure 52A -D is a schematic diagram showing the state of the injection component airbag structure in the working process of Embodiment 15 of this application, wherein... Figure 52A This diagram illustrates the uninflated state of the airbag when the sleeve is pressed against the target tissue. Figure 52B A schematic diagram showing how the balloon moves axially along the catheter towards the distal end of the needle sleeve after receiving gas from the syringe. Figure 52C A schematic diagram showing the further movement of gas from the connecting member within the airbag towards the distal end of the sleeve as the elastic sheath inflates. Figure 52D A schematic diagram showing how the air bladder contracts when the elastic sheath contracts, allowing the gas inside the air bladder to be expelled into the syringe or connector chamber.

[0272] Figure 53 This is a schematic diagram of the structure of the syringe barrel wall in the injection assembly of Embodiment 16 of this application, which has an anti-retraction part in the periphery area of ​​the through hole;

[0273] Figure 54A -B is a schematic diagram of the anti-retraction part in the injection assembly of Embodiment 16 of this application, wherein... Figure 54A To prevent the retreating part from protruding, Figure 54B The anti-retraction part is made of elastic retaining teeth;

[0274] Figure 55 This is a schematic diagram of the structure of Embodiment 17 of this application, in which a sealing member or sealing element is provided at the connection between the distal end of the syringe and the proximal end of the connector, or at the connection between the distal end of the connector and the sleeve.

[0275] Figure 56A -B is a schematic diagram of the distal end structure of the needle sleeve of the injection assembly in Embodiment 18 of this application, wherein... Figure 56A A schematic diagram showing a clamping port at the distal end of the sleeve for holding the tissue. Figure 56B A schematic diagram showing the distal end of the sleeve having a protrusion that abuts against the tissue to form a concave surface.

[0276] Marked in the image:

[0277] 1- Syringe adapter, 11- Connector, 111- Distal end of connector, 112- Proximal end of connector, 113- Dynamic seal, 12- Elastic sheath, 13- Chamber, 131- First chamber, 132- Second chamber, 133- Flexible bottom, 134- Cavity, 135- Traction component, 136- Sealing cavity, 14- Catheter, 141- Catheter wall, 142- Distal end of catheter, 143- Proximal end of catheter, 15- Through-channel, 16- Potential gap cavity, 17- Highlighting layer, 18- Touch sensor, 181- Conductive layer, 182- Electrode, 183- Response mechanism, 184- Electrode layer, 185- Electrode membrane, 19- Pore;

[0278] 2-Instrument, 21-Distal tightening part, 22-Push rod, 221-Proximal end of push rod, 222-Distal end of push rod, 23-Through hole, 24-Housing shell, 25-Piston assembly, 251-First piston, 252-Second piston, 26-Anti-recoil part, 261-Protrusion, 262-Elastic retaining teeth, 27-Seal, 28-Instrument barrel wall;

[0279] 3-Needle, 31-Needle tube, 311-Needle tube tip, 32-Needle hub, 321-Cavity, 33-Sleeve, 331-Clamping port, 332-Convex surface, 333-Distant end of sleeve, 334-Proximal end of sleeve, 34-Elastic element, 35-Airbag, 351-Bag body, 352-Inflation mechanism, 36-Through hole, 37-Sealing component;

[0280] R1 - conjunctiva, R2 - sclera, R3 - suprachoroidal space. Detailed Implementation

[0281] The present application will now be described in further detail with reference to specific embodiments. However, this should not be construed as limiting the scope of the subject matter of the present application to the following embodiments; all technologies implemented based on the content of the present application fall within the scope of the present application.

[0282] Unless otherwise specified, the terms "upper," "lower," and "left" appear in the description of specific embodiments in this application.

[0283] The terms "right," "center," "inner," and "outer," indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationship in which the product / equipment / device is typically placed during use. These terms are merely for the purpose of facilitating the description of the solution or simplifying the description in specific embodiments, enabling those skilled in the art to quickly understand the solution, and do not indicate or imply that a particular device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, they should not be construed as limitations on this application.

[0284] Furthermore, the use of terms such as "horizontal," "vertical," "suspended," and "parallel" does not imply that the corresponding device / component / element must be absolutely horizontal, vertical, suspended, or parallel. Rather, it means it can be slightly tilted or have some deviation. For example, "horizontal" merely indicates that its direction is more horizontal relative to "vertical," not that the structure must be perfectly horizontal, but can be slightly tilted. Alternatively, it can be simplified to mean that the corresponding device / component / element is in a "horizontal" or "vertical" position.

[0285] The orientation settings, such as "suspended" or "parallel," can have an error / deviation of ±10% relative to the corresponding orientation setting, more preferably within ±8%, more preferably within ±6%, more preferably within ±5%, and more preferably within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its function in the solution of this application.

[0286] Furthermore, the use of terms such as "first," "second," and "third" in terminology is merely for distinguishing identical or similar components and should not be interpreted as emphasizing or implying the relative importance of a particular component. The use of the word "approximately" in terminology sets a certain...

[0287] Error / deviation within ±10%, more preferably within ±8%, more preferably within ±6%, and even more preferably within ±5%.

[0288] Furthermore, in the description of the embodiments in this application, "several", "more than", and "several" represent at least two. They can be any number, such as two, three, four, five, six, seven, eight, or nine, and can even exceed nine.

[0289] Furthermore, in the description of the technical solutions in this application, unless otherwise explicitly specified / limited / restricted, the terms "set up," "install," "connect," "link," "equipped with," "laid out," and "arranged" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to connection methods commonly used in the art, such as welding, riveting, bolting, and threaded connections. Such connections can be mechanical, electrical, or communication connections; they can be direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components.

[0290] The syringe adapter, injection assembly, and method of use provided in this application can be widely applied to eye diseases and related conditions. These eye diseases include, but are not limited to, uveitis, glaucoma, diabetic macular edema, retinopathy, macular degeneration, retinoblastoma, and genetic diseases.

[0291] In this application, any device or method can be inserted into a patient's scleral tissue via the effective length of a needle and deliver medication into the suprachoroidal space through the inserted needle, thereby achieving the treatment of ocular diseases. In some embodiments, the effective amount of medication delivered to the suprachoroidal space provides higher therapeutic efficacy compared to the therapeutic efficacy of the same dose administered intravitreal, topically, intraocularly, non-enterally, or orally. Any device or method provided in the embodiments of this application can precisely deliver medication into the suprachoroidal space for subsequent topical delivery to nearby posterior ocular tissues (e.g., the retina and choroid) requiring treatment. The medication can be continuously released into the ocular tissues for a period of time after administration, such as hours, days, weeks, or months. In some embodiments, any device or method provided in the embodiments of this application can also improve drug bioavailability by topical administration into the ocular tissues compared to the same dose administered orally, non-enterally, or intravitreally.

[0292] The syringe adapter, injection assembly, and method of use provided in this application are applicable not only to suprachoroidal drug delivery but also to local areas of the posterior segment of the eye, such as the retinal choroidal tissue, macula, and optic nerve. The syringe sleeve, needle-equipped sleeve, injection assembly, and method of use provided in this application can also be used for gene-based therapies, delivering a drug solution containing a therapeutic gene fragment into the space above the choroid to deliver any one or more carriers selected from DNA, RNA, or oligonucleotides to the target ocular tissue.

[0293] The apparatus and methods described in the embodiments of this application can be used to treat, deliver substances to various target tissues in the eye and / or aspirate substances from various target tissues in the eye.

[0294] In this document, the term "drug" refers to any preventative, therapeutic, or diagnostic agent (e.g., a contrast agent). Drugs may be selected from suitable proteins, peptides, or fragments thereof, which may be naturally occurring, synthetic, or recombinant.

[0295] In some embodiments of this application, the syringe contains one or more pharmaceutically active liquids, which may be selected from antibodies, antiviral agents, chemotherapeutic agents, analgesics, anesthetics, aptamers, antihistamines, anti-inflammatory agents, and antitumor agents.

[0296] In this document, the term "antibody" broadly refers to any immune binding agent, such as IgG, IgM, IgA, IgD, and IgE. Antibodies can be monoclonal or polyclonal, and in some embodiments, are humanized antibodies. The term "antibody" is also used to refer to any antibody-like molecule having an antigen-binding region and comprising antibody fragments such as Fab', Fab', F(ab')2, single-domain antibodies (DAB), Fv, scFv (single-chain Fv), and engineered multivalent antibody fragments, such as bivalent, trivalent, and multivalent antibodies. Techniques for preparing and using antibodies and antibody-based constructs and fragments are well known in the art.

[0297] In some embodiments of this application, the syringe contains one or more gene therapy drugs using recombinant adeno-associated virus (rAAV) as a vector, wherein the AAV is selected from AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10, or mutants thereof; optionally, the AAV is AAV8 or a mutant thereof. The rAAV preferably contains drugs expressing the therapeutic properties of ocular diseases, such as anti-VEGF drugs, complement factor inhibitors (complement component C3, complement factor B, complement factor D), plasma kallikrein inhibitors, PDGFR inhibitors, tyrosine kinase inhibitors, integrin inhibitors, angiopoietin-2 inhibitors, and Tie-2 agonists.

[0298] In some embodiments of this application, the syringe is a pre-filled syringe, which avoids the operator from causing injury or inaccurate dosage during the drug preparation process, reduces the chance of drug use errors, effectively reduces drug residue, makes the dosage more accurate, and prevents cross-contamination because the drug is not exposed to air.

[0299] This article further explains the terms such as target location, needle specifications, effective needle length, cutting edge length, cutting edge puncture force, high-pressure air, and potential gap chambers as follows:

[0300] 1. Target location

[0301] The target location described in this article refers to any area of ​​the conjunctiva, including the superior nasal region, inferior nasal region, superior temporal region, or inferior temporal region. Specifically, any point within this region between the iris limbus and the corneal limbus, approximately 3-9 mm, 4-8 mm, 4-7 mm, 6-8 mm, 7-8 mm, or 4-5 mm from the corneal limbus. Alternatively, a distance of approximately 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, or 8 mm from the corneal limbus can be chosen.

[0302] 2. Needle specifications and parameters:

[0303] The needles used in this article can be selected from commercially available conventional injection needles such as 28G, 30G, 31G, 32G, 33G, and 34G needles, or they can be custom-made using conventional injection needle manufacturing processes.

[0304] Needle specifications: The needle tip is typically constructed to be sharp, beveled, or otherwise designed to pierce the ocular surface (e.g., the sclera). The needle used can be of any suitable gauge, such as approximately 25G, approximately 26G, approximately 27G, approximately 28G, approximately 29G, approximately 30G, approximately 31G, approximately 32G, approximately 33G, approximately 34G, approximately 35G, or approximately 36G. The needle wall can have any suitable thickness. For example, in addition to the standard wall thickness (RW), the needle wall can be designed as thin-walled (TW), extra-thin / ultra-thin-walled (XTW / UTW), or extra-thin-walled (XXTW). These names are well known to those skilled in the art. For example, the needle can be a fine-gauge cannula or needle. In some variations, the needle may have a gauge between approximately 25G and approximately 36G. In other variations, the needle may have a gauge between approximately 27G and approximately 35G. In other variations, the needle may have a specification between approximately 30G and approximately 33G.

[0305] Effective needle length: The effective needle length is the length protruding from the clamping port at the injection end of the connecting tube. The effective needle length is approximately 1400 micrometers or less, approximately 1300 micrometers or less, approximately 1200 micrometers or less, approximately 1100 micrometers or less, approximately 1000 micrometers or less, approximately 900 micrometers or less, approximately 800 micrometers or less, approximately 850 micrometers or less, approximately 700 micrometers or less, approximately 650 micrometers or less, approximately 500 micrometers or less, or approximately 450 micrometers or less. In some embodiments, the effective needle length may be approximately 700 micrometers. In other embodiments, the effective needle length may be approximately 750 micrometers, or approximately 800 micrometers, or approximately 850 micrometers, or approximately 900 micrometers, or approximately 950 micrometers, or approximately 1000 micrometers, or approximately 1100 micrometers, or approximately 1350 micrometers.

[0306] Blade length: The blade length is the straight-line distance from the inner edge of the needle wall near the liquid outlet of the needle tip to the outer edge of the needle tip on the needle outer wall. It is approximately 800 micrometers or less, approximately 700 micrometers or less, approximately 650 micrometers or less, approximately 600 micrometers or less, approximately 550 micrometers or less, approximately 500 micrometers or less, approximately 450 micrometers or less, approximately 400 micrometers or less, approximately 350 micrometers or less, approximately 300 micrometers or less, or approximately 250 micrometers or less. In some embodiments, the blade length may be approximately 550 micrometers; in other embodiments, the blade length may be approximately 700 micrometers, or approximately 650 micrometers, or approximately 600 micrometers, or approximately 500 micrometers, or approximately 450 micrometers, or approximately 300 micrometers, or approximately 250 micrometers.

[0307] Blade puncture force: The blade puncture force at the outlet of the needle tip is approximately 0.7 N or less, approximately 0.65 N or less, approximately 0.5 N or less, approximately 0.4 N or less, or approximately 0.3 N or less, to facilitate defining access to the desired location within the target tissue (e.g., suprachoroidal space and / or vitreous body) and forming a drug delivery channel. In some embodiments, the blade puncture force may be approximately 0.5 N; in other embodiments, the blade puncture force may be approximately 0.7 N, approximately 0.65 N, approximately 0.4 N, or approximately 0.3 N.

[0308] 3.rAAV-anti-VEGF

[0309] In this article, the term "rAAV-anti-VEGF" refers to rAAV containing an expression of a VEGF antagonist used to treat eye diseases, preferably aflibercept, conbercept, ranibizumab, or bevacizumab.

[0310] 4. High-pressure air

[0311] In this article, the term "high-pressure air" refers to air in a specific chamber that has been compressed to increase its pressure. This high-pressure air is compressed to a pressure higher than the air pressure in the area connected to the specific chamber, thereby generating a force that moves the needle tip toward the suprachoroidal space.

[0312] 5. Potential gap cavity

[0313] In this article, the term "potential gap cavity" refers to a potential gap formed between two or more components. When the components are fitted together, the potential gap cavity closes. When the components are under pressure, the potential gap cavity separates, forming a gap cavity. Liquid or air can enter the gap cavity. When the components are depressurized, the components fit together to expel the liquid or air from the gap cavity, thereby closing the potential gap cavity.

[0314] 6. Syringe

[0315] In this document, the term "syringe" has the definition commonly understood in the art and can include a syringe barrel and a plunger, wherein the syringe barrel may be provided with at least a syringe flange for easy gripping by the operator. The "syringe" may be pre-equipped with a needle, or the operator may select a needle suitable for patient injection. The distal end of the "syringe" may have a gradually tapering conical protrusion, i.e., the "distal constriction portion of the syringe" mentioned in the embodiments herein, or may be configured with other common molding structures.

[0316] 7. Proximal or distal

[0317] In this article, the term "distal" refers to the end that is close to or in contact with the eye tissues, and "proximal" refers to the end that is close to the operator (such as a doctor or nurse).

[0318] 8. Airbag

[0319] In this article, the term "airbag" refers to a component formed by filling a flexible chamber with compressed air or water; it utilizes the compressibility of a substance (such as air) to expand or contract the chamber, thereby providing kinetic energy to propel a component. An "airbag" can be a standalone component or a compressible space containing air or water formed by surrounding structures.

[0320] 9. Fluid seal

[0321] In this document, the term "fluid seal" can be understood to encompass both gaseous seals (i.e., seals impermeable to gas) and liquid-impermeable seals. This term is intended to express that although overall fluid impermeability is desirable, a "fluid seal" may have some very minor, acceptable leakage due to manufacturing tolerances or other practical considerations (such as the pressure applied to the seal and / or the fluid). Therefore, a "fluid seal" includes preventing fluid (including gas, liquid, and / or slurry) from passing through its sealing location at fluid pressures less than about 5 psig, less than about 10 psig, less than about 20 psig, less than about 30 psig, less than about 50 psig, less than about 75 psig, less than about 100 psig, and all intermediate values.

[0322] 10. Dynamic sealing

[0323] In this article, the term "dynamic sealing" can be understood as the sealing effect achieved by filling the gaps between moving parts through the elastic deformation or mechanical structure of sealing elements (such as rubber rings, packing, etc.) during the operation of the needle seat or needle tube. In this article, "dynamic sealing" can be a contact seal, relying on the elastic contact between the sealing element and the surface of the component to block the leakage path of fluid (including air or liquid). The sealing element of the contact seal can be an O-ring, a plug ring, a lip seal, a mechanical seal, or a packing seal, etc.

[0324] 11. Liquid drainage

[0325] In this document, the term "liquid drainage" can be understood as the drainage of fluid from the potential spacer cavity (or first chamber) into the catheter under the contraction of the elastic sheath. The drained fluid may be approximately 10% or more, approximately 20% or more, approximately 30% or more, approximately 40% or more, approximately 50% or more, approximately 60% or more, approximately 70% or more, approximately 80% or more, or approximately 90% or more of the fluid in the potential spacer cavity (or first chamber). In some embodiments, the drained fluid may be approximately 90%. In other embodiments, the drained fluid may also be approximately 80%, or approximately 70%, or approximately 60%, or approximately 50%, or approximately 40%, or approximately 30%, or approximately 20%, or approximately 10%.

[0326] 12. Pressure threshold

[0327] In this article, the pressure threshold of the elastic sheath can be understood as the injection pressure at which the injection pressure between the syringe and the needle can overcome the elastic force of the elastic sheath and cause it to begin to expand.

[0328] Example 1

[0329] Reference Figures 1A-6 As shown, this embodiment provides a syringe adapter 1, including a connector 11, the connector 11 having a chamber 13; a catheter 14, the catheter 14 passing through the connector 11 and through the chamber 13, the catheter wall 141 located in the chamber 13 having a through channel 15; and an elastic sheath 12, the elastic sheath 12 located in the chamber 13 and sleeved on the outside of the catheter wall 141, a potential gap cavity 16 being formed between the elastic sheath 12 and the catheter 14, the potential gap cavity 16 being fluidly interconnected with the catheter 14 through the through channel 15.

[0330] Specifically, in this embodiment, the syringe adapter 1 is used to be sleeved on the outside of the distal tightening part 21 of the syringe 2, wherein the proximal end 112 of the connector abuts against the syringe 2, the middle part of the connector 11 has a chamber 13, and the distal end 111 of the connector is connected to the needle 3.

[0331] The connector 11 is provided with a conduit 14, which longitudinally penetrates the connector 11 and is fluidly connected to the syringe 2. The conduit 14 has a through channel 15 in the wall 141 of the conduit 14 in the middle chamber 13 of the connector 11. In the chamber 13 of the connector 11, an elastic sheath 12 is fitted over the outside of the conduit wall 141 from one end to the other, forming a potential gap cavity 16. The potential gap cavity 16 is fluidly connected to the syringe 2 through the through channel 15. That is, the liquid in the syringe 2 can enter the potential gap cavity 16 through the through channel 15, or the liquid in the potential gap cavity 16 can enter the needle 3 through the through channel 15.

[0332] In this embodiment, the through channel 15 serves as the liquid channel between the potential gap cavity 16 and the conduit 14. In actual design, besides the attached... Figure 2 The through channel 15 shown can be configured as a hole in the conduit 14 located inside the elastic sheath 12, or it can be a conventional shape such as an opening, groove or slit.

[0333] The syringe adapter 1 described in this embodiment can be assembled using the following assembly method: Figure 2 As shown:

[0334] First, the elastic sheath 12 is fitted onto the conduit 14 to cover the through channel 15, and then glue is applied by a glue dispensing machine to fix both ends of the elastic sheath 12 onto the conduit 14.

[0335] Next, the catheter 14 with the elastic sheath 12 fitted is placed into the chamber 13 of the connector 11, so that the proximal end 143 of the catheter protrudes from the proximal end 112 of the connector 11, and the distal end 142 of the catheter protrudes from the distal end 111 of the connector 11, with the elastic sheath 12 located within the chamber 13. When assembling the syringe adapter 1 with the syringe 2 and the needle 3, the proximal end 112 of the connector 11 is fitted onto the distal tightening part 21 of the syringe 2 using a Luer head, so that at least a portion of the liquid in the syringe 2 can be delivered to the catheter 14. The distal end 111 of the connector is connected to the needle 3 using a Luer head, and at the distal end 111 of the connector, the distal end 142 of the catheter is inserted into the needle 3 and fluidly connected to the needle tube 31 of the needle 3, so that at least a portion of the liquid in the catheter 14 can be delivered to the needle tip 311 through the needle tube 31.

[0336] Different layers of the eye have different densities, which may affect the needle tip 3 outlet (i.e., the needle tip 311 where the liquid appears).

[0337] Different back pressures are generated, resulting in hydraulic changes in the liquid inside the syringe 2 during injection due to the varying back pressures. The syringe adapter 1 of this application utilizes the existing syringe structure, fixing the syringe adapter 1 to the distal tightening part 21 of the syringe 2, thereby connecting the syringe 2 and the needle 3. The operator can more intuitively determine whether the needle tip 311 has penetrated the sclera and reached the suprachoroidal space by observing the volume change of the potential gap cavity 16, the expansion of the elastic sheath 12, or by directly observing whether the liquid has entered the potential gap cavity 16, thus guiding the operator in drug injection.

[0338] like Figure 3 As shown, when the needle tip 311 of the needle 3 is located in the suprachoroidal cavity R3 at the target position, the injection pressure generated in the syringe 2 is insufficient to cause the elastic sheath 12 to expand and then disengage from the catheter wall 141. The potential gap cavity 16 remains closed, and at least a portion of the liquid in the syringe 2 can be output through the needle 3.

[0339] like Figure 4 As shown, when the needle tip 311 of the needle 3 is located in the sclera R2 at the target position, the injection pressure generated by the syringe 2 is sufficient to cause the elastic sheath 12 to expand and then disengage from the catheter wall 141, thereby opening the potential gap cavity 16 to form a gap cavity that can receive at least a portion of the liquid delivered from the syringe 2, so that the liquid in the syringe 2 cannot be output from the needle 3.

[0340] In this embodiment, when the needle tip 311 of the needle 3 is located within the sclera at the target location, the injection pressure generated by the syringe 2 is sufficient to cause the elastic sheath 12 to expand and disengage from the catheter wall 141, thereby opening the potential gap cavity 16 to form a gap cavity. The gap cavity receives at least a portion of the liquid delivered from the syringe 2, thereby balancing the hydraulic pressure within the syringe 2 and preventing the liquid within the syringe 2 from leaking from the insertion site of the needle tube 31 through the needle tip 311 due to the injection pressure within the syringe 2 exceeding the tissue back pressure generated by the sclera R2, resulting in reflux or diffusion under the conjunctiva R1.

[0341] like Figure 4-5 As shown, when the operator notices the elastic sheath 12 of the syringe adapter 1 expanding, it can be determined that the needle tip 311 of the needle 3 is located within the sclera R2 at the target location, rather than within the suprachoroidal space R3 at the target location. The operator can then apply force directly or indirectly to the needle 3 (e.g., Figure 5(As shown by the downward hollow arrow), the eye tissue in contact with the needle 3 at the target location is further compressed to shorten the distance the needle tip 311 travels from the surface of the eye tissue at the target location into the suprachoroidal space R3, thereby allowing the needle tip 311 to extend from the sclera R2 to the suprachoroidal space R3. When the needle tip 311 extends from the sclera R2 to the suprachoroidal space R3, the liquid in the needle tip 311 is released, reducing the injection pressure in the syringe 2.

[0342] like Figure 6 As shown, when the injection pressure in syringe 2 drops to a level insufficient to resist the elastic force of the elastic sheath 12, the elastic sheath 12 elastically retracts and adheres to the catheter wall 141, closing the potential gap cavity 16. Figure 6 (Unable to display), forcing the fluid in the potential space 16 to drain into the catheter 14 through the through channel 15 and delivered to the suprachoroidal space R3 through the needle 3, thereby draining the fluid in the potential space 16 and delivering it to the suprachoroidal space R3, ensuring the accuracy of the drug dosage in the suprachoroidal space R3.

[0343] In this embodiment, the conduit 14 of the connector 11 can also be the same component as the distal tightening part 21 of the syringe 2.

[0344] The proximal end 112 of the connector can be an integral component with the distal end face of the syringe 2.

[0345] Furthermore, the syringe adapter 1 described in this embodiment can also respond to changes in the injection pressure within the syringe 2 and regulate the injection pressure between the syringe 2 and the needle 3. This allows for effective control of the release rate of the substance within the syringe 2 in the suprachoroidal space, preventing excessively rapid release or sudden release.

[0346] Specifically, when the needle tip 311 of the needle 3 is located in the suprachoroidal space at the target position, the elastic sheath 12 expands in response to the increase in injection pressure of the syringe 2, opening the potential gap cavity 16 and receiving at least a portion of the liquid delivered from the syringe 2, thereby reducing the injection pressure within the syringe 2. This prevents the injection pressure within the syringe 2 from continuously increasing, which could lead to excessively rapid injection or sudden release of liquid, thus making the intraocular pressure more stable.

[0347] When the needle tip 311 of the needle 3 is located within the sclera at the target position, the elastic sheath 12 expands in response to the increased injection pressure of the syringe 2, opening the potential gap cavity 16 and receiving at least a portion of the liquid delivered from the syringe 2, thereby reducing the injection pressure within the syringe 2 and preventing the needle 3 from delivering liquid from the syringe 2. This prevents liquid leakage from the insertion site due to the injection pressure within the syringe 2 exceeding the tissue back pressure generated by the sclera, which could lead to reflux or subconjunctival diffusion.

[0348] When the needle tip 311 of the needle 3 extends and reaches the suprachoroidal space at the target location, the liquid in the needle 3 is automatically injected into the suprachoroidal space due to pressure loss. The injection pressure in the syringe 2 will decrease accordingly. The elastic sheath 12, which is in an expanded state, contracts in response to the decrease in injection pressure in the syringe 2, so as to maintain the injection pressure in the potential space cavity 16 higher than the pressure in the suprachoroidal space. In this way, the liquid in the potential space cavity 16 can be delivered to the suprachoroidal space through the needle tip 311 of the needle 3 until the elastic sheath 12 adheres to the catheter wall 141 of the connector 11, closing the potential space cavity 16 and emptying the liquid in the potential space cavity 16.

[0349] Example 2

[0350] Reference Figure 1A-1B As shown, in this embodiment, based on embodiment 1, the connector 11 opposite to the chamber 13 is provided with a transparent viewing window. Specifically, the viewing window can be a transparent material component, which is convenient for the operator to observe the expansion of the elastic sheath 12; or the connector 11 is a transparent material component. Setting a viewing window or using a transparent material component makes it convenient to observe the expansion of the elastic sheath and quickly judge whether the needle tip 311 of the needle 3 is in the suprachoroidal space of the target position.

[0351] Example 3

[0352] Reference Figure 7 As shown, in this embodiment, based on embodiment 1, the outer wall of the elastic sheath 12 is provided with a conspicuous layer 17. By setting the conspicuous layer 17, the conspicuousness of the elastic sheath 12 is improved, making it easier to observe the expansion of the elastic sheath 12 and quickly judge whether the needle tip 311 of the needle 3 is in the suprachoroidal cavity of the target position.

[0353] The eye-catching layer 17 can be coated or bonded to the outer surface of the elastic sheath 12 with eye-catching bright materials, fluorescent materials, or reflective materials.

[0354] Example 4

[0355] Reference Figure 8 In this embodiment, based on embodiment 1, the syringe adapter 1 is further provided with a touch sensor 18, which is used to emit an identifiable signal.

[0356] Specifically, the touch sensor 18 may include a conductive layer 181 disposed on the outer wall of the elastic sheath 12, an electrode 182 disposed in the chamber 13, and a response mechanism 183. When the elastic sheath 12 expands and the conductive layer 181 contacts the electrode 182 in the chamber 13, the circuit inside the touch sensor 18 closes and causes current to flow, causing the response mechanism 183 to emit an identifiable signal, enabling the doctor to quickly determine whether the needle tip 311 of the needle 3 is in the suprachoroidal space at the target location.

[0357] Among them, identifiable signals have the definition commonly understood in the field, which can use stimuli such as light, sound, mechanics, electricity, and smell to send signals to people indicating that there is a malfunction, accident or other danger.

[0358] The response mechanism 183 is provided with a flexible substrate, which can be installed on the outer wall of the syringe 2 or on the outside of the syringe adapter 1 connector 11.

[0359] Example 5

[0360] Reference Figure 9 The difference between this embodiment and embodiment 4 is that, instead of the conductive layer 181 and the electrode 182, the touch sensor 18 may include an electrode layer 184 disposed on the outer wall of the elastic sheath 12, an electrode film 185 disposed in the chamber 13 opposite to the electrode layer 184 disposed on the outer wall of the elastic sheath 12, and a response mechanism 183. A certain insulating cavity is formed between the electrode layer 184 and the electrode film 185. When the elastic sheath 12 expands and the electrode layer 184 contacts the electrode film 185, the circuit of the touch sensor 18 is closed and current flows, causing the response mechanism 183 to emit an identifiable signal, enabling the doctor to quickly determine whether the needle tip 311 of the needle 3 is in the suprachoroidal cavity R3 at the target position.

[0361] Example 6

[0362] The difference between syringe adapter 1 in this embodiment and embodiment 1 is that:

[0363] The syringe adapter 1 is used to connect the needle 3. The elastic sheath 12 expands, so that the needle tip 311 of the needle 3 extends into the suprachoroidal space R3.

[0364] And / or, the elastic sheath 12 contracts, causing the needle tip 311 to retract toward the sclera R2.

[0365] Specifically, such as Figures 10-11 As shown, the elastic sheath 12 divides the chamber 13 of the connector 11 into a first chamber 131 and a second chamber 132. At the distal end of the connector opposite to the second chamber 132 is a flexible bottom 133. The flexible bottom 133 abuts against the needle seat 32 of the needle 3, so that the needle seat 32 of the needle 3 can be sleeved on the catheter 14 and move along the axial direction of the catheter 14.

[0366] Wherein, the first chamber 131 is the potential gap chamber 16 described in Embodiment 1, and the second chamber 132 is the space portion inside the chamber 13 and outside the elastic sheath 12.

[0367] In this embodiment, the needle 3 includes a needle tube 31, a needle seat 32, and a sleeve 33. The needle seat 32 has a cavity 321, which is configured to be fluid-sealed with the needle tube 31. When the adapter 1 is connected to the needle, the distal end 142 of the catheter is always kept in the cavity 321 of the needle seat 32 and fluidly connected with the needle tube 31. The needle seat 32 is placed in the sleeve 33 so that the tip 311 of the needle tube can be exposed out of the sleeve 33 and inserted into the eye tissue.

[0368] like Figure 12 As shown, the ocular tissues can be roughly divided from the inside out into the suprachoroidal space R3, the sclera R2, and the conjunctiva R1. When the needle tip 311 of the needle 3 is located in the suprachoroidal space R3 at the target position, the elastic sheath 12 is in the first configuration (the elastic sheath is in a non-expanded state), and at least a portion of the liquid in the syringe 2 is output through the needle 3;

[0369] like Figure 13-14 As shown, when the needle tip 311 of the needle 3 is located in the sclera R2 at the target position, the elastic sheath 12 changes from the first configuration (the elastic sheath is in a non-expanded state) to the second configuration (the elastic sheath is in an expanded state). The liquid in the syringe 2 enters the first chamber 131, which increases the air pressure in the second chamber 132 and drives the flexible bottom 133 to move the needle seat 32 toward the distal end of the sleeve 33, so that the needle tip 311 of the needle 3 extends further toward the suprachoroidal space R3 at the target position.

[0370] When the needle tip 311 of the needle 3 extends to the target location in the suprachoroidal space R3, the elastic sheath 12 changes from a second configuration to a first configuration in the chamber 13, causing the liquid in the first chamber 131 to flow out and be delivered to the suprachoroidal space R3 via the needle 3, until the elastic sheath 12 changes to the first configuration, thereby causing the elastic sheath 12 to adhere to the catheter wall 141 of the connector 11 and close the first chamber 131. Figure 15 (Unable to display), forcing the liquid in the first chamber 131 to drain into the catheter 14 through the through-channel 15, and then delivering it to the suprachoroidal space R3 through the needle 3, until the elastic sheath 12 and the catheter wall 141 of the connector 11 are fitted together to close the first chamber 131, thereby emptying the first chamber 131 and allowing the liquid in the first chamber 131 to be delivered to the suprachoroidal space R3, ensuring the accuracy of the drug dosage in the suprachoroidal space R3.

[0371] Among them, such as Figure 16As shown, when the elastic sheath 12 changes from the second configuration to the first configuration, the space of the second chamber 132 increases as the elastic sheath 12 contracts, causing the air pressure inside the second chamber 132 to continuously decrease. This results in the air pressure inside the second chamber 132 being insufficient to resist the elastic force of the flexible bottom 133, causing the flexible bottom 133 to resume contraction. This drives the needle seat 32 to move towards the connector 11, causing the needle tip 311 of the needle 3 to gradually retract along the needle path formed by the needle tube within the scleral R2 tissue at the target location. This not only allows the liquid to further diffuse in the suprachoroidal space R3, but also makes the intraocular pressure more stable during liquid delivery within the syringe 2.

[0372] In this embodiment, the flexible bottom 133 can be an elastic membrane.

[0373] The syringe adapter 1 described in this embodiment can also respond to hydraulic changes within the syringe 2, causing the elastic sheath 12 to switch between a second configuration and a first configuration, thereby regulating the injection pressure between the syringe 2 and the needle 3. This allows for effective control of the release rate of the substance within the syringe 2 in the suprachoroidal space, preventing excessively rapid release or sudden release.

[0374] When the needle tip 311 of the needle 3 is located in the suprachoroidal space, the elastic sheath 12 will also change to the second configuration in response to the increase of the injection pressure of the syringe 2, receive at least a portion of the liquid delivered from the syringe 2, reduce the injection pressure in the syringe 2, and allow the liquid in the syringe 2 to be delivered smoothly to the suprachoroidal space.

[0375] When the needle tip 311 is located within the sclera, the elastic sheath 12 changes to a second configuration in response to the increase in injection pressure of the syringe 2, receiving at least a portion of the liquid delivered from the syringe 2, reducing the injection pressure within the syringe, so that the needle cannot deliver liquid from the syringe.

[0376] When the needle tip 311 extends and reaches the target location in the suprachoroidal cavity, the liquid in the needle 3 automatically depressurizes and is injected into the suprachoroidal cavity. The injection pressure in the syringe 2 decreases accordingly. The elastic sheath 12, in its second configuration, responds to the decrease in injection pressure in the syringe 2 by switching to its first configuration to maintain the injection pressure in the first chamber 131 higher than the pressure in the suprachoroidal cavity. This allows the liquid in the first chamber 131 to be delivered to the suprachoroidal cavity via the needle tip 311 of the needle 3 until the elastic sheath 12 adheres to the catheter wall 141 of the connector 11, closing the first chamber 131.

[0377] Example 7

[0378] The difference between the syringe adapter in this embodiment and that in embodiment 1 is:

[0379] The syringe adapter 1 is used to connect the needle 3. The elastic sheath 12 expands, so that the needle tip 311 of the needle 3 extends into the suprachoroidal space R3.

[0380] And / or, the elastic sheath 12 contracts, causing the needle tip 311 to retract toward the sclera R2.

[0381] Specifically, such as Figure 17-18 As shown, the syringe adapter 1 also includes a fluid-sealed cavity 134 (i.e., a cavity 134 located below the chamber 13) between the connector 11 and the needle 3. The cavity 134 is configured to communicate with the second chamber 132 and is fitted with a needle seat 32 of the needle 3, so that the needle seat 32 can be fitted onto the catheter 14 and move axially along the catheter 14 within the cavity 134.

[0382] The needle hub 32 is further provided with a cavity 321 connected to the needle tube 31. The cavity 321 is configured to receive the distal end 142 of the catheter, so that when the needle hub 32 moves along the axial direction of the catheter 14 in the cavity 134, the distal end 142 of the catheter is always kept in the cavity 321 and is fluidly connected to the needle tube 31.

[0383] The needle tube 31 can extend out of the cavity 134, so that when the needle tube tip 311 of the needle tube 31 moves along the axial direction of the catheter 14 in the cavity 134, it can extend into the suprachoroidal space R3 of the target tissue.

[0384] A dynamic seal 113 may be provided at the connection between the distal end of the cavity 134 and the needle tube 31. The dynamic seal 113 is configured such that when the needle seat 32 moves axially along the guide tube 14 within the cavity 134, the connection between the needle tube 31 and the distal end 111 of the connector will not leak air, so as to ensure that the cavity 13 is in a sealed state, allowing the air in the cavity 13 to circulate between the cavity 134 and the second chamber 132, providing a power source for the needle seat 32 to move axially along the guide tube 14 within the cavity 134.

[0385] Specifically, when the elastic sheath 12 expands, the space inside the second chamber 132 is compressed, and the air inside the second chamber 132 is compressed to exert a force on the needle hub 32 in the direction of the needle tip 311, so that the needle hub 32 can move along the catheter 14 in the cavity 134 towards the needle tip 311, thereby enabling the needle tip 311 to extend into the suprachoroidal space R3 of the target tissue.

[0386] As the needle hub 32 moves along the catheter 14 towards the needle tip 311 within the cavity 134, the air within the cavity 134 (air located in the distal portion of the cavity 134) is compressed and exerts a reaction force on the needle hub 32. When the needle hub 32 has moved a certain area within the cavity 134, and the reaction force exerted by the air within the cavity 134 on the needle hub 32 is equal to the force exerted by the air within the cavity 134 on the needle hub 32, the needle hub 32 will no longer move towards the needle tip 311. This prevents the needle tip 311 from excessively extending towards the suprachoroidal space R3 of the target tissue, puncturing the choroid and the ocular tissue below, and causing injection failure.

[0387] When the elastic sheath 12 contracts, the space inside the second chamber 132 expands, causing the air pressure inside the second chamber 132 to decrease. When the reaction force exerted by the air in the cavity 134 on the needle holder 32 exceeds the force exerted by the air in the second chamber 132 on the needle holder 32, the needle holder can move along the guide tube 14 toward the syringe 2, thereby driving the needle tip 311 to move along the needle path formed by the needle tip 311 in the eye tissue toward the syringe 2, away from the suprachoroidal space and back to the sclera.

[0388] The dynamic seal described in this embodiment can be a contact seal, which relies on the elastic contact between the sealing element and the surface of the needle tube 31 to block the air leakage channel. The sealing element of the contact seal can be an O-ring, a plug ring, a lip seal, a mechanical seal, or a packing seal, etc.

[0389] In this embodiment, the syringe adapter 1, in conjunction with the syringe 2 and the needle 3, enables:

[0390] like Figure 19 As shown, when the needle tip 311 of the needle 3 is located in the suprachoroidal cavity R3 at the target position, the injection pressure generated in the syringe 2 is insufficient to expand the elastic sheath 12 to generate sufficient air pressure in the second chamber 132 to push the needle hub 32 to move along the conduit 14 in the cavity 134 toward the distal end 333 of the sleeve of the needle 3, and at least a portion of the liquid in the syringe 2 can be output through the needle 3.

[0391] like Figure 20-21 As shown, when the needle tip 311 of the needle 3 is located in the sclera R2 at the target position, the elastic sheath 12 expands to open the potential gap cavity 16 to receive the liquid in the syringe 2, while generating sufficient air pressure in the second chamber 132 to push the needle seat 32 to move along the catheter 14 towards the distal end 333 of the sleeve in the cavity 134, so that the needle tip 311 extends further towards the suprachoroidal space R3 at the target position.

[0392] When the needle tip 311 of the needle 3 extends to the suprachoroidal space R3 at the target location, the liquid in the needle tip 311 of the needle 3 is released in the suprachoroidal space R3, thereby reducing the injection pressure in the syringe 2.

[0393] like Figure 22 As shown, when the injection pressure in the syringe 2 is insufficient to resist the elastic force of the elastic sheath 12, the elastic sheath 12 elastically retracts and fits against the catheter wall 141 of the connector 11, closing the potential gap cavity 16, forcing the liquid in the potential gap cavity 16 to be discharged into the catheter 14 through the through channel 15 provided by the connector 11 catheter 14, and delivered to the suprachoroidal cavity R3 through the needle 3.

[0394] During the elastic retraction of the elastic sheath 12 and its contact with the catheter wall 141 of the connector 11, the space inside the second chamber 132 expands, causing a decrease in the air pressure within the second chamber 132. When the air pressure inside the cavity 134 exceeds the air pressure inside the second chamber 132, the needle hub can move along the catheter 14 toward the syringe 2, thereby driving the needle tip 311 to move along the needle path formed by the needle tip 311 in the ocular tissue toward the syringe 2, away from the suprachoroidal space. This not only allows the liquid to diffuse further in the suprachoroidal space R3, but also makes the intraocular pressure more stable during the liquid delivery process in the syringe 2.

[0395] Example 8

[0396] The difference between this embodiment and Embodiment 1 is that:

[0397] The syringe adapter 1 is used to connect the needle 3. The elastic sheath 12 expands, so that the needle tip 311 of the needle 3 extends into the suprachoroidal space R3.

[0398] And / or, the elastic sheath 12 contracts, causing the needle tip 311 to retract toward the sclera R2.

[0399] Specifically, such as Figure 23-24 As shown, the syringe adapter 1 also includes a traction component 135, which is partially located in the chamber 13 and partially located in the cavity 134. The two ends of the traction component are respectively fixed to the proximal end 112 of the connector and the needle seat 32 of the needle 3, and are configured to allow the needle seat 32 of the needle 3 to move axially along the catheter 14 within the cavity 134 under the action of the elastic sheath 12.

[0400] In this embodiment, the traction component 135 can be installed by laser dispensing adhesive to both ends of the traction component 135.

[0401] The needle hub 32 is provided with a cavity 321 that allows the catheter 14 to slide axially within the cavity 321. The cavity 321 is configured to be connected to the needle tube 31 of the needle tip 3, so that the catheter 14 is fluidly connected to the needle tube 31 within the cavity 321.

[0402] The cavity 321 is configured to receive the distal end 142 of the catheter, such that when the needle hub 32 moves along the axial direction of the catheter 14 within the cavity 134, the distal end 142 of the catheter remains within the cavity 321 and is fluidly connected to the needle tube 31.

[0403] The needle tube 31 can extend out of the chamber 13, so that when the needle tube tip 311 of the needle tube 31 moves along the axial direction of the catheter 14 in the cavity 134, it can extend to the suprachoroidal space R3 of the target tissue.

[0404] In this embodiment, the syringe adapter 1, in conjunction with the syringe 2 and the needle 3, enables:

[0405] like Figure 25 As shown, when the needle tip 311 of the needle 3 is located in the suprachoroidal space R3 at the target position, the injection pressure generated in the syringe 2 is insufficient to expand the elastic sheath 12 to move the traction member 135 away from the direction of the catheter 14, and at least a portion of the liquid in the syringe 2 can be output through the needle 3.

[0406] like Figure 26-27 As shown, when the needle tip 311 of the needle 3 is located in the sclera R2 at the target position, the elastic sheath 12 expands to open the potential gap cavity 16 to receive the liquid in the syringe 2. At the same time, the traction member 135 moves with the expansion of the elastic sheath 12, driving the needle seat 32 to move along the axial direction of the catheter 14 toward the distal end 333 of the sleeve within the cavity 134, so that the needle tip 311 extends further toward the suprachoroidal space R3 at the target position.

[0407] like Figure 27 As shown, when the needle tip 311 of the needle 3 extends to the suprachoroidal space R3 at the target location, the liquid in the needle tip 311 of the needle 3 is released in the suprachoroidal space R3, thereby reducing the injection pressure in the syringe 2.

[0408] like Figure 28 As shown, when the injection pressure in the syringe 2 is insufficient to resist the elastic force of the elastic sheath 12, the elastic sheath 12 elastically retracts and fits against the catheter wall 141 of the connector 11, closing the potential gap cavity 16, forcing the liquid in the potential gap cavity 16 to be discharged into the catheter 14 through the through channel 15 provided in the catheter 14, and delivered to the suprachoroidal cavity R3 through the needle 3.

[0409] Wherein, when the arc-shaped surface of the traction component 135 and the elastic sheath 12 abuts is fixedly connected to the elastic sheath, such as Figure 28 As shown, when the elastic sheath 12 elastically retracts to drain the liquid in the potential gap cavity 16 into the catheter 14, the traction component 135 moves toward the catheter 14, guiding the traction component 135 to drive the needle hub 32 to move along the catheter 14 away from the distal end 333 of the sleeve within the cavity 134, causing the needle tip 311 located in the suprachoroidal cavity R3 to gradually retract along the needle path formed by the needle in the sclera R2 tissue at the target location.

[0410] Example 9

[0411] Reference Figures 1A-9 As shown, this embodiment provides an injection assembly, including any of the syringe adapter 1, syringe 2, and needle 3 from embodiments 1-5.

[0412] The distal tightening portion 21 of the syringe 2 is connected to the proximal end 112 of the connector of the syringe adapter 1.

[0413] The needle 3, the needle hub 32 of the needle 3 is connected to the distal end 111 of the connector of the syringe adapter 1;

[0414] Syringe 2 and needle 3 are fluidly connected via syringe adapter 1.

[0415] When the needle tip 311 of the needle 3 is located in the suprachoroidal cavity R3 at the target location, the injection pressure generated in the syringe 2 is insufficient to cause the elastic sheath 12 to expand and disengage from the catheter wall 141, the potential gap cavity 16 remains closed, and at least a portion of the liquid in the syringe 2 can be output through the needle 3.

[0416] When the needle tip 311 of the needle 3 is located within the sclera R2 at the target position, the injection pressure generated within the syringe 2 is sufficient to cause the elastic sheath 12 to expand and disengage from the catheter wall 141, opening the potential gap cavity 16 and receiving at least a portion of the liquid delivered from the syringe, preventing the liquid within the syringe 2 from being output from the needle 3.

[0417] The syringe 2 is equipped with a plunger 22, with the distal end 222 of the plunger placed inside the syringe 2 and the proximal end 221 of the plunger placed outside the syringe 2. The plunger 22 is configured to bear force on the proximal end 221. The syringe 2, syringe adapter 1, and needle 3 are configured together such that, Figure 3-4 As shown:

[0418] When the needle tip 311 of the needle 3 is placed in the suprachoroidal cavity R3 at the target location, the injection pressure generated in the syringe 2 is insufficient to cause the elastic sheath 12 to expand and disengage from the catheter wall 141, the potential gap cavity 16 remains closed, and at least a portion of the liquid in the syringe 2 can be output through the needle 3.

[0419] When the needle tip 311 of the needle 3 is located within the sclera R2 at the target location, the injection pressure generated by the syringe 2 is sufficient to cause the elastic sheath 12 to expand and disengage from the catheter wall 141, opening the potential gap cavity 16 and receiving at least a portion of the liquid delivered from the syringe, so that the liquid in the syringe cannot be output from the needle.

[0420] When the operator notices or feels the elastic sheath 12 expanding (e.g. Figure 4-5 When the needle tip 311 is located in the sclera R2 at the target location rather than in the suprachoroidal space R3 at the target location, it can be determined that the needle tip 311 is located in the sclera R2 at the target location rather than in the suprachoroidal space R3 at the target location. Force F can be applied directly or indirectly to the needle tip 3 to further compress the tissue in the area in contact with the needle tip 3 at the target location, thereby shortening the distance from the surface of the tissue in the target location area to the suprachoroidal space R3, so that the needle tip 311 can extend from the sclera R2 to the suprachoroidal space R3.

[0421] When the needle tip 311 of the needle 3 extends from the sclera R2 to the suprachoroidal space R3, the liquid in the needle tip 311 is released, thereby reducing the injection pressure in the syringe 2.

[0422] Among them, the injection pressure in syringe 2 drops to a level insufficient to resist the elastic force of elastic sheath 12 (e.g. Figure 6 When the elastic sheath 12 retracts elastically and adheres to the catheter wall 141 of the connector 11, it closes the potential gap cavity 16, forcing the liquid in the potential gap cavity 16 to drain into the catheter 14 through the through-channel 15 provided in the connector 11 catheter 14, and then delivered to the suprachoroidal space R3 through the needle 3. This allows the liquid in the potential gap cavity 16 to be emptied and delivered to the suprachoroidal space R3, ensuring the accuracy of the drug dosage in the suprachoroidal space R3.

[0423] Furthermore, the syringe 2, syringe adapter 1, and needle 3 are configured together to enable...

[0424] The syringe adapter 1 can respond to hydraulic changes within the syringe 2, causing the elastic sheath 12 to expand or contract elastically, thereby regulating the injection pressure between the syringe 2 and the needle 3. This controls the release rate of the liquid within the syringe 2 in the suprachoroidal cavity, preventing excessively rapid release or sudden release.

[0425] When the needle tip 311 of the needle 3 is located in the suprachoroidal space, the syringe adapter 1 responds to the increased injection pressure of the syringe 2 by opening the potential gap cavity 16 to receive at least a portion of the liquid delivered from the syringe 2, thereby reducing the injection pressure within the syringe 2. This prevents the liquid in the syringe 2 from being released too quickly or suddenly in the suprachoroidal space.

[0426] When the needle tip 311 is located in the sclera, the syringe adapter 1 responds to the increase in injection pressure of the syringe 2 by opening the potential gap cavity 16 to receive at least a portion of the liquid delivered from the syringe 2, and reducing the injection pressure in the syringe 2 so that the liquid in the syringe 2 cannot be output from the needle.

[0427] When the needle tip 311 extends and reaches the target location in the suprachoroidal space, the liquid in the needle 3 automatically depressurizes and is injected into the suprachoroidal space. The injection pressure in the syringe 2 decreases accordingly. The syringe adapter 1 responds to the decrease in injection pressure by gradually compressing the potential gap cavity 16 to maintain the injection pressure in the potential gap cavity 16 higher than the pressure in the suprachoroidal space. This allows the liquid in the potential gap cavity 16 to be delivered to the suprachoroidal space via the needle tip 311 until the elastic sheath 12 and the catheter wall 141 of the connector 11 adhere and close the potential gap cavity 16.

[0428] In this embodiment, in addition to the push rod 22, the component that pushes the liquid in the syringe 2 toward the distal tightening part 21 of the syringe 2 can also be a conventional syringe liquid pushing component such as an injection pump or a medical air pump.

[0429] Example 10

[0430] Reference Figures 10-16 As shown, this embodiment provides an injection assembly, including the syringe adapter 1, syringe 2, and needle 3 as in embodiment 6.

[0431] The distal tightening portion 21 of the syringe 2 is connected to the proximal end 112 of the connector of the syringe adapter 1.

[0432] The needle hub 32 of the needle 3 is connected to the distal end 111 of the connector of the syringe adapter 1;

[0433] Syringe 2 and needle 3 are fluidly connected via syringe adapter 1.

[0434] When the needle tip 311 of the needle 3 is located in the suprachoroidal space R3 at the target location, the elastic sheath 12 is in the first configuration, and at least a portion of the liquid in the syringe 2 is output through the needle 3.

[0435] When the needle tip 311 of the needle 3 is located in the sclera R2 at the target position, the elastic sheath 12 changes from the first configuration to the second configuration (i.e., the elastic sheath 12 expands), the liquid in the syringe 2 enters the first chamber 131, which increases the air pressure in the second chamber 132 and drives the flexible bottom 133 to move the needle seat 32 toward the distal end of the sleeve 33, so that the needle tip 311 of the needle 3 extends further toward the suprachoroidal cavity R3 at the target position. When the needle tip 311 of the needle 3 extends to the suprachoroidal cavity R3 at the target position, the elastic sheath 12 changes from the second configuration to the first configuration in the chamber 13 (i.e., the elastic sheath 12 contracts), the liquid in the first chamber 131 flows out and is delivered to the suprachoroidal cavity R3 through the needle.

[0436] The flexible bottom 133 is connected to the needle seat 32 of the needle tip 3, such as... Figure 16 As shown, when the elastic sheath 12 changes from the second configuration to the first configuration in the chamber 13, the space of the second chamber 132 increases as the elastic sheath 12 contracts, causing the air pressure inside the second chamber 132 to continuously decrease. This results in the air pressure inside the second chamber 132 being insufficient to resist the elastic force of the flexible bottom 133, causing the flexible bottom 133 to resume contraction. This drives the needle hub 32 to move towards the connector 11, causing the needle tip 311 of the needle 3 to gradually retract along the needle path formed by the needle tube within the scleral R2 tissue at the target location. This not only allows the liquid to further diffuse in the suprachoroidal space R3, but also makes the intraocular pressure more stable during liquid delivery within the syringe 2.

[0437] Furthermore, the syringe 2, syringe adapter 1, and needle 3 are configured together to enable...

[0438] (1) When the needle tip 311 of the needle 3 is located in the suprachoroidal space, the elastic sheath 12 will also change to a second configuration in response to the increase in the injection pressure of the syringe 2, receiving at least a portion of the liquid delivered from the syringe 2 and reducing the injection pressure in the syringe 2. This can prevent the liquid in the syringe 2 from being released too quickly or suddenly in the suprachoroidal space;

[0439] (2) When the needle tip 311 is located in the sclera, the elastic sheath 12 changes to the second configuration in response to the increase of the injection pressure of the syringe 2, receives at least a portion of the liquid delivered from the syringe 2, reduces the injection pressure in the syringe 2, and prevents the liquid in the syringe 2 from being output from the needle.

[0440] (3) When the needle tip 311 extends and reaches the target position of the suprachoroidal cavity, the liquid in the needle 3 loses pressure and is automatically injected into the suprachoroidal cavity. The injection pressure in the syringe 2 will decrease accordingly. The elastic sheath 12 in the second configuration responds to the decrease in the injection pressure in the syringe 2 and changes to the first configuration to maintain the injection pressure in the first chamber 131 higher than the pressure in the suprachoroidal cavity, so that the liquid in the first chamber 131 can be delivered to the suprachoroidal cavity through the needle tip 311 of the needle 3 until the elastic sheath 12 closes the first chamber 131.

[0441] The flexible bottom 133 is connected to the needle seat 32 of the needle 3. When the elastic sheath 12 changes from the second configuration to the first configuration, the air pressure in the second chamber 132 decreases. When the air pressure in the second chamber 132 is insufficient to resist the elastic force of the flexible bottom 133, the flexible bottom 133 recovers its contraction, causing the needle seat 32 to move towards the connector 11, so that the needle tip 311 of the needle 3 gradually retracts along the needle channel formed by the needle tube in the sclera R2 tissue at the target position.

[0442] Example 11

[0443] Reference Figures 17-22 As shown, this embodiment provides an injection assembly, including the syringe adapter 1, syringe 2, and needle 3 as in embodiment 7.

[0444] The distal tightening portion 21 of the syringe 2 is connected to the proximal end 112 of the connector of the syringe adapter 1.

[0445] The needle hub of the needle 3 is connected to the distal end 111 of the connector of the syringe adapter 1;

[0446] Syringe 2 and needle 3 are fluidly connected via syringe adapter 1.

[0447] In this embodiment, the injection assembly, in cooperation with the syringe adapter 1, syringe 2, and needle 3, enables:

[0448] When the needle tip 311 of the needle 3 is located in the suprachoroidal cavity R3 at the target position, and the injection pressure generated in the syringe 2 is insufficient to cause the elastic sheath 12 to expand and generate sufficient air pressure in the second chamber 132 to push the needle seat 32 to move along the catheter 14 towards the distal end 333 of the sleeve in the cavity 134, at least a portion of the liquid is delivered from the syringe 2 via the needle 3.

[0449] When the needle tip 311 of the needle 3 is located in the sclera R2 at the target position, the elastic sheath 12 expands to open the potential gap cavity 16 to receive the liquid in the syringe 2, while the second chamber 132 generates sufficient air pressure to push the needle seat 32 to move along the catheter 14 towards the distal end 333 of the sleeve in the cavity 134, so that the needle tip 311 extends further towards the suprachoroidal space R3 at the target position; when the needle tip 311 of the needle 3 extends to the suprachoroidal space R3 at the target position, the liquid in the needle tip 311 of the needle 3 is released in the suprachoroidal space R3, thereby reducing the injection pressure in the syringe 2;

[0450] When the injection pressure in syringe 2 is insufficient to resist the elastic force of elastic sheath 12, elastic sheath 12 elastically retracts and fits against the catheter wall 141 of connector 11, closing the potential gap cavity 16, forcing the liquid in the potential gap cavity 16 to be discharged into the catheter 14 through the through channel 15 provided by connector 11 catheter 14, and delivered to the suprachoroidal cavity R3 through needle 3.

[0451] During the elastic retraction of the elastic sheath 12 and its contact with the catheter wall 141 of the connector 11, the space inside the second chamber 132 expands, causing a decrease in the air pressure within the second chamber 132. When the air pressure in the cavity 134 exceeds the air pressure inside the second chamber 132, the needle hub can move along the catheter 14 toward the syringe 2, thereby driving the needle tip 311 to move along the needle path formed by the needle tip 311 in the ocular tissue toward the syringe 2, away from the suprachoroidal space. This not only allows the liquid to diffuse further in the suprachoroidal space R3, but also makes the intraocular pressure more stable during the liquid delivery process in the syringe 2.

[0452] Example 12

[0453] Reference Figures 23-28 As shown, this embodiment provides an injection assembly, including the syringe adapter 1, syringe 2, and needle 3 as in embodiment 8.

[0454] Among them, the distal tightening part 21 of the syringe 2 is connected to the proximal end 112 of the connector of the syringe adapter 1;

[0455] The needle 3, the needle hub 32 of the needle 3 is connected to the distal end 111 of the connector of the syringe adapter 1;

[0456] Syringe 2 and needle 3 are fluidly connected via syringe adapter 1.

[0457] In this embodiment, the injection assembly, with the cooperation of syringe adapter 1, syringe 2, and needle 3, enables:

[0458] When the needle tip 311 of the needle 3 is located in the suprachoroidal space R3 at the target location, the injection pressure generated in the syringe 2 is insufficient to cause the elastic sheath 12 to expand and the traction member 135 to move away from the catheter 14, so that at least a portion of the liquid is delivered from the syringe 2 via the needle 3.

[0459] When the needle tip 311 of the needle 3 is located in the sclera R2 at the target position, the elastic sheath 12 expands to open the potential gap cavity 16 to receive the liquid in the syringe 2. At the same time, the traction component 135 moves in the direction away from the catheter 14, and guides the distal end of the traction component 135 to drive the needle seat 32 to move along the axial direction of the catheter 14 toward the distal end of the sleeve 333 in the cavity 134, so that the needle tip 311 extends further toward the suprachoroidal space R3 at the target position.

[0460] When the needle tip 311 of the needle 3 extends to the suprachoroidal space R3 at the target location, the liquid in the needle tip 311 of the needle 3 is released in the suprachoroidal space R3, thereby reducing the injection pressure in the syringe 2.

[0461] When the injection pressure in syringe 2 is insufficient to resist the elastic force of elastic sheath 12, elastic sheath 12 elastically retracts and fits against the catheter wall 141 of connector 11, closing the potential gap cavity 16, forcing the liquid in the potential gap cavity 16 to be discharged into the catheter 14 through the through channel 15 provided in the catheter 14, and delivered to the suprachoroidal cavity R3 through needle 3.

[0462] The traction component 135 is fixedly connected to the elastic sheath 12, such as... Figure 28 As shown, when the elastic sheath 12 elastically retracts to drain the liquid in the potential gap cavity 16 into the catheter 14, the traction component 135 moves toward the catheter 14, guiding the traction component 135 to drive the needle hub 32 to move along the catheter 14 away from the distal end 333 of the sleeve within the cavity 134, causing the needle tip 311 located in the suprachoroidal cavity R3 to gradually retract along the needle path formed by the needle in the sclera R2 tissue at the target location.

[0463] Example 13

[0464] Reference Figure 29-32 As shown, the difference between this embodiment and the injection assembly in Embodiment 9 is that the needle 3 is further provided with an elastic element 34. The needle hub 32 is used to mount and fix the needle tube 31, allowing the needle tip 311 to protrude from the distal end 333 of the sleeve. The catheter 14 is fluidly connected to the needle tube 31 via the needle hub 32. In this embodiment, the proximal end 334 of the sleeve of the needle 3 abuts against the elastic element 34, and the elastic element 34 abuts against the needle hub 32. The elastic element 34 can compress and deform by increasing the tissue back pressure (f) at the target location, causing the sleeve 33 to move towards the syringe 2, thereby further extending the length of the needle tube 31 protruding from the distal end 333 of the sleeve.

[0465] In actual operation, when the elastic sheath 12 expands, as... Figure 25 As shown, the operator can determine that the needle tip 311 of the current needle 3 is located within the sclera R2 at the target location, rather than within the suprachoroidal space R3 at the target location. The operator can apply further force (F) to the tissue contacted by the distal end 333 of the sleeve via the syringe 2, plunger 22, or other components through the needle hub 32, increasing the tissue back pressure (f) of the target tissue and compressing the elastic element 34. Under the action of the tissue back pressure (f) of the target tissue, the sleeve 33 moves towards the syringe 2, thereby further extending the length of the needle tube protruding from the distal end 333 of the sleeve, allowing the needle tip 311 to extend into the suprachoroidal space R3 at the target location.

[0466] When the needle tip 311 of the needle 3 extends into the suprachoroidal space R3 at the target location, as Figure 26 As shown, the liquid in the needle tip 311 of the needle 3 is released in the suprachoroidal space R3, reducing the injection pressure in the syringe 2. If the injection pressure in the syringe 2 is insufficient to resist the elastic force of the elastic sheath 12, the elastic sheath 12 elastically retracts and adheres to the catheter wall 141 of the connector 11, closing the potential gap cavity 16, forcing the liquid in the potential gap cavity 16 to drain into the catheter 14 through the through-channel 15, and then delivered to the suprachoroidal space R3 via the needle 3.

[0467] Example 14

[0468] Reference Figure 33-4 As shown in Figure 3, the difference between this embodiment and the injection assembly in Embodiment 9 is that the injection assembly mainly includes:

[0469] A syringe adapter 1 with an air hole 19 is provided on the chamber 13 of the connector 11.

[0470] The syringe 2 has a through hole 23 on the syringe barrel wall 28. The syringe 2 mainly includes:

[0471] The housing 24 is sealed and fitted onto the syringe 2. The housing 24 is configured to allow air to circulate between the syringe 2 and the chamber 13 of the connector 11 through the through hole 23 in the syringe barrel wall 28.

[0472] The plunger 22 has its distal end 222 placed inside the syringe 2 and its proximal end 221 placed outside the syringe 2. By applying force to the proximal end 221 of the plunger, the liquid inside the syringe 2 is delivered to the needle 3.

[0473] And the piston assembly 25 inside the syringe 2, which moves axially inside the syringe 2 under the actuation of the push rod 22, so that at least part of the air inside the syringe 2 enters the second chamber 132 through the housing 24, and the air pressure in the second chamber 132 is sufficient to move the needle seat 32 sleeved in the cavity 134 of the connector 11 toward the distal end 333 of the sleeve of the needle 3, so that the needle tip 311 of the needle 3 can protrude from the distal end 333 of the sleeve;

[0474] The needle 3 mainly includes a needle tube 31, a sleeve 33 for connecting the distal end 111 of the connector, and a needle seat 32 fitted inside the cavity 134 of the connector 11. The needle seat 32 is provided with a cavity 321, which is configured to be fluid-sealed with the needle tube 31 of the needle 3, so that the distal end 142 of the catheter is always kept in the cavity 321 of the needle seat 32 and fluidly connected with the needle tube 31.

[0475] When the proximal end 221 of the plunger is subjected to force, under the combined action of the syringe 2, syringe adapter 1, and needle 3, the following occurs:

[0476] like Figure 35 and 36 As shown, before the needle tip 311 of the needle 3 protrudes from the distal end 333 of the sleeve, a force is applied to the proximal end 221 of the push rod to cause the piston assembly 25 to move axially within the syringe 2, compressing the air inside the syringe 2. The air is then introduced into the second chamber 132 of the connector 11 through the through hole 23 and the housing 24 of the syringe 2. The air pressure in the second chamber 132 is sufficient to move the needle seat 32, which is sleeved in the cavity 134 of the connector 11, toward the distal end 333 of the sleeve of the needle 3, so that the needle tip 311 of the needle 3 can protrude from the distal end 333 of the sleeve and be inserted into the eye tissue from the position contacted by the distal end 333 of the sleeve.

[0477] When the needle tip 311 of the needle 3 is located in the suprachoroidal space R3 at the target location, such as Figure 37 As shown, the injection pressure generated inside the syringe 2 is insufficient to cause the elastic sheath 12 to expand and detach from the contact with the catheter wall 141, and at least a portion of the liquid in the syringe 2 is delivered via the needle 3.

[0478] When the needle tip 311 of the needle 3 is located within the sclera R2 at the target position, such as Figure 38 and 39As shown, the injection pressure generated by the syringe 2 is sufficient to cause the elastic sheath 12 to expand and disengage from the catheter 14, opening the potential gap cavity 16 and receiving at least a portion of the liquid delivered from the syringe 2 through the through channel 15, preventing the liquid in the syringe 2 from being delivered from the needle 3, and further compressing the air in the second chamber 132 of the connector 11, thereby generating sufficient pressure to push the needle seat 32 to move along the catheter 14 towards the distal end 333 of the sleeve within the cavity 134, causing the needle tip 311 to extend further towards the suprachoroidal space R3 at the target location, reaching the suprachoroidal space R3 at the target location; when the needle tip 311 of the needle 3 extends from the sclera R2 to the suprachoroidal space R3, the liquid in the needle tip 311 of the needle 3 is released in the suprachoroidal space R3, reducing the injection pressure in the syringe 2;

[0479] When the injection pressure inside syringe 2 is insufficient to resist the elastic force of elastic sheath 12, such as Figure 40 As shown, the elastic sheath 12 elastically retracts and fits against the catheter wall 141 of the connector 11, closing the potential gap cavity 16, forcing the liquid in the potential gap cavity 16 to drain into the catheter 14 through the through channel 15, and then delivered to the suprachoroidal cavity R3 through the needle 3.

[0480] During the elastic retraction of the elastic sheath 12 and its contact with the catheter wall 141 of the connector 11, the space inside the second chamber 132 expands, reducing the air pressure within the second chamber 132. When the reaction force exerted by the air in the cavity 134 on the needle hub 32 exceeds the force exerted by the air in the second chamber 132 on the needle hub 32, the needle hub can move along the catheter 14 toward the syringe 2, thereby driving the needle tip 311 to move along the needle path formed by the needle tip 311 in the ocular tissue toward the syringe 2, away from the suprachoroidal space. This not only allows the liquid to diffuse further in the suprachoroidal space R3, but also makes the intraocular pressure more stable during the liquid delivery process in the syringe 2.

[0481] In this embodiment, the syringe adapter can also have a flexible bottom 133 at the distal end 111 of the connector opposite to the chamber 13, such as... Figure 41 As shown, when the elastic sheath 12 elastically retracts, it closes the potential gap cavity 16 (because the potential gap cavity 16 is closed, it is impossible to...). Figure 41 As the liquid in the catheter 14 is discharged into the catheter (as shown in the image), the flexible bottom 133 recovers its contraction under the action of the elastic sheath 12, driving the needle seat 32 to move towards the connector 11, so that the needle tip 311 of the needle tube 3 gradually retracts along the needle channel formed by the needle tube 31 in the sclera R2 tissue at the target position.

[0482] The syringe adapter in this embodiment may further include a traction component 135, which is partially located in the chamber 13 and partially located in the cavity 134. Both ends of the traction component are respectively fixed to the proximal end 112 of the connector and the needle seat 32 of the needle 3. Figure 42 As shown, when the elastic sheath 12 elastically retracts, it closes the potential gap cavity 16 (because the potential gap cavity 16 is closed, it is impossible to...). Figure 42 As the liquid in the tube (as shown in the image) is discharged into the catheter 14, the traction component 135 moves toward the catheter 14 under the action of the elastic sheath 12. The distal end of the traction component 135 is guided to drive the needle hub 32 to move along the catheter 14 away from the distal end 333 of the sleeve within the cavity 134, so that the needle tip 311 located in the suprachoroidal space R3 gradually retracts along the needle path formed by the needle in the sclera R2 tissue at the target position.

[0483] Among them, such as Figures 34-4 As shown in Figure 3, the piston assembly 25 mainly includes a first piston 251 that contacts the distal end of the push rod 22 and a second piston 252 that contacts the liquid. The compressed air formed in the syringe chamber 13 between the first piston 251 and the second piston 252 is sufficient to push the needle seat 32 to move due to the air pressure in the chamber 13 of the connector 11, causing the tip of the needle tube to move toward the distal end 333 of the sleeve and be inserted into the tissue at the target position. However, it is insufficient to push the second piston 252 to move toward the distal tightening part 21 of the syringe 2 to increase the injection pressure in the syringe 2.

[0484] When the needle tip 311 of the needle 3 is located in the sclera R2 at the target position, the first piston 251 can block the through hole 23 provided on the wall of the syringe 2 to ensure the airtightness of the second chamber 132 and prevent the second chamber 132 from being depressurized through the through hole 23 provided on the wall of the syringe 2, which would affect the extension effect of the needle tip 311 from the sclera R2 to the suprachoroidal cavity R3.

[0485] Example 15

[0486] Reference Figures 43A-44B As shown, the difference between this embodiment and the injection assembly in Embodiment 10 is that the proximal end 334 of the sleeve of the needle 3 in the injection assembly is connected to the distal end 111 of the connector. Figure 43B The needle holder 32 is fitted inside the sleeve 33 and can movably abut against the proximal end 334 of the sleeve. An air bladder 35 is provided between the proximal end 334 of the sleeve and the needle holder 32. A through hole 36 is provided at the proximal end 334 of the sleeve to allow air to pass between the housing 24 and the air bladder 35. An air hole 19 is provided at the distal end 111 of the connector to allow air to pass between the second chamber 132 of the connector 11 and the air bladder 35 inside the sleeve 33.

[0487] The proximal end 221 of the push rod is subjected to force, and with the combined action of the syringe 2, syringe adapter 1, and needle 3, the following occurs:

[0488] like Figure 45 and Figure 46 As shown, when the needle tip 311 of the needle 3 is not in contact with the tissue surface at the target location, the force applied at the proximal end 221 of the push rod is sufficient to cause the piston assembly 25 to move axially within the inner wall of the syringe 2, compressing the air inside the syringe 2 to form high-pressure air. The high-pressure air inside the syringe 2 is then introduced into the air bladder 35 of the sleeve 33 through the housing 24, causing the needle hub 32 to move within the sleeve 33 towards the distal end 333 of the sleeve, thereby exposing the needle tip 311 to the end face of the distal end 333 of the sleeve and inserting it into the eye tissue at the target location.

[0489] like Figure 47 As shown, when the needle tip 311 of the needle 3 is located in the suprachoroidal cavity R3 at the target position, the injection pressure generated in the syringe 2 is insufficient to cause the elastic sheath 12 to expand and detach from the contact with the catheter wall 141, and the potential gap cavity 16 remains closed, at least a portion of the liquid is delivered from the syringe 2 via the needle 3.

[0490] As shown in the figure Figure 48 and 49 As shown, when the needle tip 311 of the needle 3 is located within the sclera R2 at the target position, the injection pressure generated by the syringe 2 is sufficient to cause the elastic sheath 12 to expand and disengage from the catheter 14, opening the potential gap cavity 16 and receiving at least a portion of the liquid delivered from the syringe 2, preventing the liquid in the syringe 2 from being output from the needle 3. Furthermore, compressed air is generated in the second chamber 132 of the chamber 13 of the connector 11, forming high-pressure air. This high-pressure air enters the air bladder 35 of the sleeve 33 through the air hole 19 at the distal end 111 of the connector, squeezing the needle seat 32. This causes the needle seat 32 to move further towards the distal end of the sleeve 33, driving the needle tip 311 to extend towards the suprachoroidal space R3 at the target position, reaching the suprachoroidal space R3. If the needle tip 311 of the needle 3 extends from the sclera R2 to the suprachoroidal space R3, the liquid within the needle tip 311 of the needle 3 is released in the suprachoroidal space R3, reducing the injection pressure within the syringe 2.

[0491] When the injection pressure in syringe 2 is insufficient to resist the elastic force of elastic sheath 12, elastic sheath 12 elastically retracts and fits against the catheter wall 141 of connector 11, closing the potential gap cavity 16, forcing the liquid in the potential gap cavity 16 to enter the catheter 14 through the through channel 15, and delivered to the suprachoroidal space R3 through needle 3.

[0492] like Figure 50 As shown, when the elastic sheath 12 elastically retracts, it closes the potential gap cavity 16 (because the potential gap cavity 16 is closed, it is impossible to...). Figure 40As the liquid in the tube (as shown in the image) is discharged into the catheter 14, the airbag 35 moves toward the catheter 14 under the action of the elastic sheath 12, causing the needle hub 32 to move along the catheter 14 away from the distal end 333 of the sleeve, so that the needle tip 311 located in the suprachoroidal space R3 gradually retracts along the needle channel formed by the needle in the sclera R2 tissue at the target position.

[0493] In this embodiment, the airbag 35, as shown Figure 43B As shown: The proximal end 334 of the sleeve of the injection assembly needle 3 is connected to the distal end 111 of the connector. The needle seat 32 is fitted inside the sleeve 33 and movably abuts against the proximal end 334 of the sleeve. An air bladder 35 is provided between the proximal end 334 of the sleeve and the needle seat 32. An air hole 19 is provided at the distal end 111 of the connector to allow air to circulate between the second chamber 132 of the connector 11 and the air bladder 35 inside the sleeve 33, and to circulate with the through hole 23 to allow air from the syringe to enter. In this embodiment, the air bladder 35 is as follows... Figures 52A-52D As shown: It mainly includes a bladder body 351 and an inflation mechanism 352 provided on the bladder body 351. The inflation mechanism 352 allows air to be exchanged between the air bladder 35 and the shell 24 through the through hole 36. The inflation mechanism 352 allows air to be exchanged between the air bladder 35 and the chamber 13 of the syringe adapter 1 connector 11 through the air hole 19.

[0494] Specifically, such as Figure 52B As shown, the operator applies force to the proximal end 221 of the plunger to cause the piston assembly 25 to axially compress the air inside the syringe 2. The air is then introduced into the inflation mechanism 352 of the airbag through the through hole 23, the housing 24 of the syringe 2, and the through hole 36 of the needle. The compressed air inside the syringe 2 enters the airbag 35, and the airbag 35 expands towards the distal end 333 of the sleeve. This pushes the needle seat 32 against the airbag 35 towards the distal end 333 of the sleeve, thereby exposing the needle tip 311 to the distal end of the sleeve and inserting it into the eye tissue at the target location.

[0495] like Figure 52C As shown, when the elastic sheath 12 expands, the air in the second chamber 132 is compressed by the elastic sheath 12, and thus enters the inflation mechanism 352 of the airbag through the air hole 19 provided at the distal end 111 of the connector, causing the airbag 35 to expand further. This further pushes the needle seat 32 against the airbag 35 towards the distal end 333 of the sleeve, causing the needle seat 32 to move further towards the distal end 333 of the sleeve, driving the needle tip 311 to extend towards the suprachoroidal cavity R3 at the target position. If the needle tip 311 of the needle 3 extends from the sclera R2 to the suprachoroidal cavity R3, the liquid in the needle tip 311 of the needle 3 can be released in the suprachoroidal cavity R3, reducing the injection pressure in the syringe 2.

[0496] like Figure 52DAs shown, when the elastic sheath 12 elastically retracts and adheres to the catheter wall 141 of the connector 11 to close the potential gap cavity 16, the internal space of the second chamber 132 is restored. Then, the air in the airbag 35 is drawn in through the air hole 19 by the inflation mechanism 352, causing the airbag 35 to contract and drive the needle seat 32 to move towards the elastic sheath 12. This causes the needle tip 311 located in the suprachoroidal space R3 to gradually retract along the needle path formed by the needle in the sclera R2 tissue at the target position.

[0497] Among them, such as Figure 43C As shown, the airbag 35 described in this embodiment can also be introduced into the airbag 35 through the air hole 19 of the syringe adapter 1 and the through hole 23 of the syringe 2, thereby regulating the air pressure in the airbag 35 to drive the needle seat 32 to move axially along the catheter 14, thereby realizing the movement of the needle tip 311 in the eye tissue.

[0498] Among them, such as Figure 55 As shown, in this embodiment, the airbag 35 can also be a sealed cavity 136 formed by the needle seat 32, the sleeve 33 and the distal end 111 of the syringe adapter 1 connector. The sealed cavity 136 is in communication with the housing 24 through the through hole 36 and with the chamber 13 of the syringe adapter 1 connector 11 through the air hole 19.

[0499] Example 16

[0500] like Figure 53 As shown, based on the injection assembly of Embodiment 14, the syringe barrel 28 is provided with an anti-retraction part 26. The first piston 251 contacts the anti-retraction part 26 when blocking the through hole 23. The anti-retraction part 26 is configured such that the first piston 251 in contact with it can only move in the direction toward the distal tightening part 21 within the syringe 2.

[0501] Specifically, an anti-retraction part 26 is provided in the periphery of the through hole 23 on the syringe barrel wall 28. When the anti-retraction part 26 contacts and blocks the through hole 23 on the syringe 2 wall, the first piston 251 can only move towards the distal tightening part 21 in the syringe 2, and cannot move away from the distal tightening part 21. This prevents the first piston 251 from moving away from the distal tightening part 21 and affecting the extension effect of the needle tip 311 from the sclera R2 to the suprachoroidal cavity R3.

[0502] Among them, such as Figure 54A As shown, the anti-retraction part 26 is a protrusion 261 provided in the periphery of the through hole 23, which protrudes in the direction of the movement of the first piston 251 toward the distal tightening part 21 of the syringe 2, that is, the protrusion 261 is inclined toward the tightening part 21.

[0503] Among them, such as Figure 54BAs shown, the anti-retraction part 26 may also be an elastic locking tooth 262 provided in the periphery of the through hole provided on the syringe wall, which protrudes in the direction of the movement of the first piston 251 toward the distal tightening part 21 of the syringe 2, that is, the elastic locking tooth 262 extends obliquely toward the tightening part 21.

[0504] The anti-recoil part 26 described in this embodiment can also be any other anti-recoil component commonly used by those skilled in the art that can prevent the first piston 251 from moving away from the distal tightening part 21 due to changes in hydraulic pressure inside the syringe after the first piston 251 has blocked the through hole 23 on the syringe wall.

[0505] Example 17

[0506] like Figure 55 As shown, based on the injection assembly of Embodiment 14, a seal 27 is placed between the distal tightening part 21 and the proximal end 112 of the connector. The seal 27 is fitted onto the proximal end 112 of the connector. When the distal tightening part 21 of the syringe 2 abuts against the proximal end 112 of the connector, the seal 27 fits the distal tightening part 21 to prevent pressure leakage inside the syringe 2, which would affect the operator's accuracy in quickly judging whether the needle tip 311 of the needle 3 is in the suprachoroidal space R3 of the target position by whether the elastic sheath 12 expands.

[0507] In this embodiment, the injection assembly may also have a sealing member 37 between the distal end of the syringe adapter 1 and the needle 3. The sealing member 37 is fitted onto the distal end 111 of the connector. When the distal end 111 of the connector abuts against the sleeve 33 of the needle 3, the sealing member 37 fits against the sleeve 33 of the needle 3, preventing pressure leakage in the air bladder 35, thereby affecting the needle seat 32 to move further toward the distal end 333 of the sleeve, so that the needle tip 311 extends to the suprachoroidal space R3 at the target position.

[0508] The “sealant” and “sealant component” mentioned in this embodiment are materials or parts commonly used by those skilled in the art to prevent gas or liquid from leaking between adjacent mating surfaces.

[0509] Example 18

[0510] Based on the injection component of Example 15, such as Figure 56AAs shown, the distal end 333 of the sleeve is provided with a clamping port 331 for clamping the eye tissue at the target location. The clamping port 331 has an annular end face, the minimum inner diameter of which is 1mm-3mm. During use, the needle tube 31 is inserted into the injection point needle seat 32 or the sleeve 33 for injection. The minimum inner diameter of the annular end face of the clamping port 331 refers to the length of the shortest line segment passing through the injection point and with both ends located inside the clamping port 331. The injection point is located at the center of this line segment. According to experimental results disclosed in CN115670788A (An ophthalmic injection assembly, injection device, and method of use), when the minimum inner diameter is 1-3mm, the area of ​​the eye tissue within the clamping port 331 is moderate. The eye tissue can form a noticeable protrusion within the clamping port 331, facilitating injection operation, enabling accurate positioning, and preventing fluid diffusion under the conjunctiva. Therefore, the clamping port 331 described in this embodiment not only facilitates contact with eye tissue and fixes the position of the syringe 2, thus improving the success rate of injection and enabling the drug solution to be delivered smoothly to the target site, but also effectively prevents the backflow of liquid from spreading under the conjunctiva if leakage occurs in the scleral tissue.

[0511] In addition, such as Figure 56B As shown, the end face of the distal end 333 of the sleeve of the needle 3 is formed as a convex surface 332, so that when the distal end 333 of the sleeve of the needle 3 comes into contact with the eye tissue at the target location, the eye tissue at the target location can fully contact the distal end 333 of the sleeve of the needle 3 and form a concave area, so that when the distal end 333 of the sleeve comes into contact with the target surface, a substantial fluid seal is formed, thereby reducing and / or eliminating the leakage of injected drugs along the needle path to the ocular surface during the injection process.

[0512] Example 19

[0513] This embodiment provides a method for using a syringe adapter, such as... Figures 1A-6 It adopts the syringe adapter 1 of the above embodiments 1-5, and the method of use includes:

[0514] S1. The operator abuts the proximal end 112 of the connector of syringe adapter 1 against the distal end tightening part 21 of syringe 2, and abuts the distal end 111 of the connector of syringe adapter 1 against the needle 3, so that syringe adapter 1, syringe 2 and needle 3 are fluidly connected.

[0515] S2. When the needle contacts the target eye tissue, the operator applies force to the plunger 22 of syringe 2, causing the plunger 22 to move within syringe 1, thus creating hydraulic pressure within syringe 2. This, combined with the work of syringe adapter 1, syringe 2, and needle 3, results in:

[0516] When the needle tip 311 of the needle 3 is located in the suprachoroidal cavity R3 at the target location, the injection pressure generated in the syringe 2 is insufficient to cause the elastic sheath 12 to expand and disengage from the catheter wall 141, the potential gap cavity 16 remains closed, and at least a portion of the liquid in the syringe 2 is output through the needle 3.

[0517] When the needle tip 311 of the needle 3 is located within the sclera R2 at the target position, the injection pressure generated by the syringe 2 is sufficient to cause the elastic sheath 12 to expand and disengage from the catheter wall 141 and open the potential gap cavity 16 to form a gap cavity, receiving at least a portion of the liquid delivered from the syringe 2, so that the liquid in the syringe 2 cannot be output from the needle 3.

[0518] S3. When the elastic sheath 12 of the syringe adapter 1 is found to expand, the operator can determine that the needle tip 311 of the needle 3 is located in the sclera R2 at the target position rather than in the suprachoroidal space R3 at the target position. The operator can apply force directly or indirectly to the needle 3 to further compress the tissue in the area where the needle 3 contacts the target position, thereby shortening the distance from the needle tip 311 of the needle 3 from the surface of the tissue in the target position area to the suprachoroidal space R3, so that the needle tip 311 of the needle 3 can extend from the sclera R2 to the suprachoroidal space R3.

[0519] S4. When the needle tip 311 of the needle 3 extends from the sclera R2 to the suprachoroidal space R3, the liquid in the needle tip 311 is released, thereby reducing the injection pressure in the syringe 2.

[0520] S5. When the injection pressure in the syringe drops to a level insufficient to resist the elastic force of the elastic sheath 12, the elastic sheath 12 elastically retracts and adheres to the catheter wall 141 of the connector 11, closing the potential gap cavity 16. This forces the liquid in the potential gap cavity 16 to drain into the catheter 14 through the through-channel 15 of the connector 11 catheter 14, and then deliver it to the suprachoroidal space R3 via the needle 3. This empties the liquid from the potential gap cavity 16 and delivers it to the suprachoroidal space R3, ensuring the accuracy of the drug dosage administered in the suprachoroidal space R3.

[0521] Example 20

[0522] This embodiment provides a method for using a syringe adapter, such as... Figure 10-16 It adopts the syringe adapter 1 of Embodiment 6 above, and its usage method includes:

[0523] S1. The operator abuts the proximal end 112 of the connector of syringe adapter 1 against the distal end tightening part 21 of syringe 2, and abuts the distal end 111 of the connector of syringe adapter 1 against the needle 3, so that syringe adapter 1, syringe 2 and needle 3 are fluidly connected.

[0524] S2. When the needle contacts the target eye tissue, the operator applies force to the plunger 22 of syringe 2, causing the plunger 22 to move within syringe 1, thus creating hydraulic pressure within syringe 2. This, combined with the work of syringe adapter 1, syringe 2, and needle 3, results in:

[0525] When the needle tip 311 of the needle 3 is located in the suprachoroidal space R3 at the target location, the elastic sheath 12 is configured in a first configuration to deliver at least a portion of the liquid from the syringe 2 via the needle 3.

[0526] When the needle tip 311 of the needle 3 is located in the sclera R2 at the target position, the elastic sheath 12 is configured in the chamber 13 and changes from the first configuration to the second configuration. The liquid of the syringe 2 enters the first chamber 131 (same as the potential gap chamber 16), so that the needle 3 cannot deliver liquid from the syringe 2.

[0527] When the elastic sheath 12 is configured in the chamber 13 and changes from the first configuration to the second configuration, the air in the second chamber 132 is compressed to form high-pressure air, and squeezes the flexible bottom 133 to produce elastic deformation and move towards the needle tip, thereby driving the needle tip 311 of the needle 3 to extend further towards the target location of the suprachoroidal cavity R3.

[0528] S3. When the needle tip 311 of the needle 3 extends and reaches the target position of the suprachoroidal space R3, the liquid in the needle tip 311 is released, which reduces the injection pressure in the syringe 2. The elastic sheath 12 is configured in the chamber 13 and changes from the second configuration to the first configuration, which closes the first chamber 131, drains the liquid in the first chamber 131, and delivers it to the suprachoroidal space R3 through the needle 3.

[0529] If the flexible bottom 133 is fixedly connected to the needle seat 32 of the needle 3, when the elastic sheath 12 is configured in the chamber 13 and changes from the second configuration to the first configuration, the air pressure in the second chamber 132 decreases and is insufficient to resist the elastic force of the flexible bottom 133, causing the flexible bottom 133 to recover and contract, which in turn causes the needle tip 311 of the needle 3 to gradually retract along the needle path formed in the sclera R2 tissue at the target position.

[0530] Example 21

[0531] This embodiment provides a method for using a syringe adapter, such as... Figure 17-22 It adopts the syringe adapter of Embodiment 7 above, and the method of use includes:

[0532] S1. The operator abuts the proximal end 112 of the connector of syringe adapter 1 against the distal end tightening part 21 of syringe 2, and abuts the distal end 111 of the connector of syringe adapter 1 against the needle 3, so that syringe adapter 1, syringe 2 and needle 3 are fluidly connected.

[0533] S2. When the needle contacts the target eye tissue, the operator applies force to the plunger 22 of syringe 2, causing the plunger 22 to move within syringe 1, thus creating hydraulic pressure within syringe 2. This, combined with the work of syringe adapter 1, syringe 2, and needle 3, results in:

[0534] When the needle tip 311 of the needle 3 is located in the suprachoroidal cavity R3 at the target position, the injection pressure generated in the syringe 2 is insufficient to cause the elastic sheath 12 to expand and generate sufficient air pressure in the cavity 134 to push the needle seat 32 to move along the catheter 14 towards the distal end 333 of the sleeve in the cavity 134, and at least a portion of the liquid in the syringe 2 is output through the needle 3.

[0535] When the needle tip 311 of the needle 3 is located in the sclera R2 at the target position, the elastic sheath 12 expands to open the potential gap cavity 16 to receive the liquid in the syringe 2, while generating sufficient air pressure in the cavity 134 to push the needle seat 32 to move along the catheter 14 towards the distal end 333 of the sleeve within the cavity 134, so that the needle tip 311 extends further towards the suprachoroidal space R3 at the target position; when the needle tip 311 of the needle 3 extends to the suprachoroidal space R3 at the target position, the liquid in the needle tip 311 of the needle 3 is released in the suprachoroidal space R3, thereby reducing the injection pressure in the syringe 2;

[0536] When the injection pressure in syringe 2 is insufficient to resist the elastic force of elastic sheath 12, elastic sheath 12 elastically retracts and fits against the catheter wall 141 of connector 11, closing the potential gap cavity 16, forcing the liquid in the potential gap cavity 16 to drain into catheter 14 through through channel 15, and delivered to suprachoroidal space R3 through needle 3.

[0537] Example 22

[0538] This embodiment provides a method for using a syringe adapter, such as... Figure 23-28 It adopts the syringe adapter of Embodiment 8 above, and the method of use includes:

[0539] S1. The operator abuts the proximal end 112 of the connector of syringe adapter 1 against the distal end tightening part 21 of syringe 2, and abuts the distal end 111 of the connector of syringe adapter 1 against the needle 3, so that syringe adapter 1, syringe 2 and needle 3 are fluidly connected.

[0540] S2. When the needle contacts the target eye tissue, the operator applies force to the plunger 22 of syringe 2, causing the plunger 22 to move within syringe 1, thus creating hydraulic pressure within syringe 2. This, combined with the work of syringe adapter 1, syringe 2, and needle 3, results in:

[0541] When the needle tip 311 of the needle 3 is located in the suprachoroidal space R3 at the target position, the injection pressure generated in the syringe 2 is insufficient to cause the elastic sheath 12 to expand and move the traction member 135, and at least a portion of the liquid in the syringe 2 is output through the needle 3.

[0542] When the needle tip 311 of the needle 3 is located in the sclera R2 at the target position, the elastic sheath 12 expands to open the potential gap cavity 16 to receive the liquid in the syringe 2. At the same time, the traction component 135 moves, guiding the traction component 135 to drive the needle hub 32 along the catheter 14 towards the distal end 333 of the sleeve in the cavity 134, so that the needle tip 311 extends further towards the suprachoroidal space R3 at the target position.

[0543] When the needle tip 311 of the needle 3 extends to the suprachoroidal space R3 at the target location, the liquid in the needle tip 311 of the needle 3 is released in the suprachoroidal space R3, reducing the injection pressure in the syringe 2. When the injection pressure in the syringe 2 is insufficient to resist the elastic force of the elastic sheath 12, the elastic sheath 12 elastically retracts and fits against the catheter wall 141 of the connector 11, closing the potential gap cavity 16, forcing the liquid in the potential gap cavity 16 to pass through the channel 15 and drain into the catheter 14, and then be delivered to the suprachoroidal space R3 via the needle 3.

[0544] The traction component 135 is fixedly connected to the elastic sheath 12. When the elastic sheath 12 elastically retracts to drain the liquid in the potential gap cavity 16 into the catheter 14, the traction component 135 moves toward the catheter 14. The traction component 135 guides the needle hub 32 to move along the axis of the catheter 14 toward the distal end 333 of the sleeve within the cavity 134, so that the needle tip 311 located in the suprachoroidal cavity R3 gradually retracts along the needle path formed by the needle in the sclera R2 tissue at the target position.

[0545] Example 23

[0546] A method of using an injection component, employing the injection component of Embodiment 9 described above, includes the following steps: Figure 1A-6 As shown:

[0547] S1. Place the distal end of the plunger 22 into the syringe 2. The operator applies force to the proximal end 221 of the plunger exposed in the syringe 2. With the cooperation of the syringe 2, syringe adapter 1, and needle 3, the following occurs:

[0548] When the needle tip 311 of the needle 3 is located in the suprachoroidal space R3 at the target location, the injection pressure generated in the syringe 2 is insufficient to cause the elastic sheath 12 to expand and disengage from the catheter wall 141, and at least a portion of the liquid in the syringe is output through the needle 3.

[0549] When the needle tip 311 of the needle 3 is located in the sclera R2 at the target position, the injection pressure generated in the syringe 2 is sufficient to cause the elastic sheath 12 to expand and disengage from the catheter wall 141, opening the potential gap cavity 16 and receiving at least a portion of the liquid delivered from the syringe 2 through the through channel 15, so that the liquid in the syringe cannot be output from the needle 3.

[0550] S2. When the needle comes into contact with the ocular tissue at the target location, the operator applies force to the needle 3 through the syringe 2, the plunger 22 or other components, so that the tissue in the area where the needle 3 comes into contact at the target location is further compressed to shorten the distance that the needle tip 311 travels from the surface of the tissue at the target location to the suprachoroidal space R3, so that the needle tip 311 can extend from the sclera R2 to the suprachoroidal space R3.

[0551] When the needle tip 311 of the needle 3 extends from the sclera R2 to the suprachoroidal space R3, the liquid in the needle tip 311 is released in the suprachoroidal space R3, thereby reducing the injection pressure in the syringe 2.

[0552] S3. When the injection pressure in syringe 2 drops to a level insufficient to resist the elastic force of elastic sheath 12, elastic sheath 12 elastically retracts and adheres to the catheter wall 141 of connector 11, closing the potential gap cavity 16. This forces the liquid in the potential gap cavity 16 to drain into catheter 14 through through channel 15 and be delivered to suprachoroidal space R3 via needle 3, thereby emptying the liquid in the potential gap cavity 16 and delivering it to suprachoroidal space R3, ensuring the accuracy of the drug dosage in suprachoroidal space R3.

[0553] Example 24

[0554] A method for using an injection component, employing the injection component of Embodiment 15 described above, includes the following steps: Figure 43A-53 As shown:

[0555] The distal end of the plunger 22 is placed inside the syringe 2. When the needle contacts the eye tissue at the target location, the operator applies force to the proximal end 221 of the plunger exposed in the syringe 2. With the combined action of the syringe 2, syringe adapter 1, and needle 3:

[0556] S1. Applying a force to the proximal end 221 of the plunger to cause the piston assembly 25 to move axially within the inner wall of the syringe 2, compressing the air inside the syringe 2 to form high-pressure air, which is then introduced into the air bladder 35 of the sleeve 33 through the housing 24, causing the needle hub 32 to move within the sleeve 33 toward the distal end 333 of the sleeve, thereby exposing the needle tip 311 to the distal end 333 of the sleeve and inserting it into the eye tissue at the target location;

[0557] When the needle tip 311 of the needle 3 is located in the suprachoroidal cavity R3 at the target location, the injection pressure generated in the syringe 2 is insufficient to cause the elastic sheath 12 to expand and detach from the contact with the catheter wall 141, the potential gap cavity 16 remains closed, and at least a portion of the liquid in the syringe 2 is output through the needle 3.

[0558] When the needle tip 311 of the needle 3 is located within the sclera R2 at the target location, the injection pressure generated by the syringe 2 is sufficient to cause the elastic sheath 12 to expand and disengage from the catheter 14, opening the potential gap cavity 16 and receiving at least a portion of the liquid delivered from the syringe 2, preventing the liquid in the syringe 2 from being output from the needle 3.

[0559] S2. When the elastic sheath 12 expands and disengages from the catheter 14, compressed air is generated in the second chamber 132 of the connector 11 to form high-pressure air. The air enters the air bladder 35 of the sleeve 33 through the air hole 19 provided at the distal end 111 of the connector and squeezes the needle seat 32, causing the needle seat 32 to move further towards the distal end of the sleeve 33. This drives the needle tip 311 to extend towards the suprachoroidal cavity R3 at the target position and reach the suprachoroidal cavity R3 at the target position.

[0560] S3. When the needle tip 311 of the needle 3 extends from the sclera R2 to the suprachoroidal space R3, the liquid in the needle tip 311 of the needle 3 is released in the suprachoroidal space R3, thereby reducing the injection pressure in the syringe 2.

[0561] S4. When the injection pressure in the syringe 2 is reduced to a level insufficient to resist the elastic force of the elastic sheath 12, the elastic sheath 12 elastically retracts and adheres to the catheter wall 141 of the connector 11, closing the potential gap cavity 16, forcing the liquid in the potential gap cavity 16 to enter the catheter 14 through the through channel 15, and then delivered to the suprachoroidal space R3 through the needle 3.

[0562] S5. When the elastic sheath 12 elastically retracts and fits against the catheter wall 141 of the connector 11, the second chamber 132 draws air from the airbag 35 through the air hole 19 provided at the distal end 111 of the connector, so that the pressure in the airbag 35 is reduced to be insufficient to resist the elastic force of the airbag 35. The airbag 35 contracts and drives the needle seat 32 to move towards the distal end 111 of the connector, so that the needle tip 311 of the needle 3 gradually retracts along the needle path of the eye tissue at the target position to the sclera R2.

[0563] Example 25

[0564] A method for using an injection component, employing the injection component of Embodiment 10 described above, includes the following steps: Figure 10-16 As shown:

[0565] The distal end of the plunger 22 is placed inside the syringe 2. When the needle contacts the eye tissue at the target location, the operator applies force to the proximal end 221 of the plunger exposed in the syringe 2. With the combined action of the syringe 2, syringe adapter 1, and needle 3:

[0566] S1. When the needle tip 311 of the needle 3 is located in the suprachoroidal space R3 at the target location, the elastic sheath 12 is configured in a first configuration, and at least a portion of the liquid in the syringe 2 is output through the needle 3.

[0567] S2. When the needle tip 311 of the needle 3 is located in the sclera R2 at the target position, the elastic sheath 12 is configured in the chamber 13 and changes from the first configuration to the second configuration. The liquid of the syringe 2 enters the first chamber 131, which compresses the air in the second chamber 132 to form high-pressure air, and squeezes the flexible bottom to produce elastic deformation and move towards the needle tip, thereby driving the needle tip 311 of the needle 3 to extend further towards the suprachoroidal space R3 at the target position.

[0568] S3. When the needle tip 311 of the needle 3 extends and reaches the target position of the suprachoroidal space R3, the liquid in the needle tip 311 is released, which reduces the injection pressure in the syringe 2. The elastic sheath 12 is configured in the chamber 13 and changes from the second configuration to the first configuration, which closes the first chamber, drains the liquid in the first chamber into the catheter 14, and delivers it to the suprachoroidal space R3 through the needle 3.

[0569] S4. The elastic sheath 12 is configured in the chamber 13 and changes from the second configuration to the first configuration. The air pressure in the second chamber 132 decreases and is insufficient to resist the elastic force of the flexible bottom 133, causing the flexible bottom 133 to recover and contract. This causes the needle tip 311 of the needle 3 to gradually retract along the needle path formed in the sclera R2 tissue at the target location.

[0570] Example 26

[0571] Based on Example 1, the syringe adapter 1 provided in this example is used to connect the syringe 2 and the needle 3.

[0572] The elastic sheath 12 can switch between the first configuration and the second configuration.

[0573] Specifically, such as Figure 1A-6 As shown, when the needle tip 311 of the needle 3 is located in the suprachoroidal cavity R3, the elastic sheath 12 is in the first configuration. At this time, the potential gap cavity 16 is closed, that is, the volume of the potential gap cavity 16 is close to zero, and at least part of the liquid can be delivered from the syringe 2 via the needle 3.

[0574] When the needle tip 311 is located within the sclera R2, the elastic sheath 12 is in the second configuration or changes from the first configuration to the second configuration, or changes from the second configuration to the first configuration. At this time, the potential gap cavity 16 is opened. The potential gap cavity 16 receives at least a portion of the liquid delivered from the syringe 2 through the through channel 15, so that the needle 3 cannot deliver liquid from the syringe 2.

[0575] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application. The specific components arranged in a particular direction or position as shown in the above schematic diagrams and / or embodiments can be adaptively adjusted. Similarly, the methods or steps described herein can be adjusted in the order of specific methods and / or steps. Although the embodiments have been specifically shown and described, it should be understood that various changes in form and detail are possible.

[0576] Although the apparatus and methods described herein are provided for delivering drugs in the space above the choroid, in other embodiments, the apparatus and methods described herein can be adapted to deliver any suitable therapeutic fluid to any part of the eye, such as the cornea, conjunctiva, retinal region, or vitreous body. In other embodiments, any of the apparatus and methods described herein can be used to deliver any suitable therapeutic fluid to any desired target tissue.

Claims

1. A syringe adapter (1), characterized in that, include: The connector (11) has a chamber (13); The catheter (14) passes through the chamber (13) and through the connector (11), and the catheter wall (141) located in the chamber (13) is provided with a through channel (15); An elastic sheath (12) is located inside the chamber (13), sleeved on the outside of the conduit (14) and forming a potential gap cavity (16) between the conduit (14) and the conduit (14). The potential gap cavity (16) is in fluid communication with the conduit (14) through the through channel (15).

2. The syringe adapter (1) according to claim 1, characterized in that, The syringe adapter (1) is used to connect the syringe (2) and the needle (3) and to regulate the injection pressure between the syringe (2) and the needle (3).

3. A syringe adapter (1) according to claim 2, characterized in that, The syringe (2) is provided with a plunger (22), the distal end (222) of which is housed within the syringe (2), and the plunger (22) is configured to be subjected to force at the proximal end (221) of the plunger; wherein the syringe adapter (1), the syringe (2), and the needle (3) are configured such that: (1) When the needle tip (311) of the needle (3) is located in the second region of the target tissue and the injection pressure between the syringe (2) and the needle (3) is higher than the pressure threshold for the expansion of the elastic sheath (12), the elastic sheath (12) expands, thereby opening the potential gap cavity (16) to receive at least a portion of the substance delivered from the syringe (2), and reducing the injection pressure between the syringe (2) and the needle (3); (2) When the needle tip (311) of the needle (3) is located in the second region of the target tissue, and the injection pressure between the syringe (2) and the needle (3) is lower than the pressure threshold of the expansion of the elastic sheath (12), the elastic sheath (12) closes the potential gap cavity (16), so that at least a portion of the substance in the syringe (2) is output through the needle (3); (3) When the needle tip (311) of the needle (3) is located in the first region of the target tissue, and the injection pressure between the syringe (2) and the needle (3) is higher than the pressure threshold for the expansion of the elastic sheath (12), the elastic sheath (12) expands, thereby opening the potential gap cavity (16) to receive at least a portion of the substance delivered from the syringe (2), reducing the injection pressure between the syringe (2) and the needle (3) so that the substance in the syringe (2) cannot be output from the needle (3); (4) When the needle tip (311) of the needle (3) extends from the first region of the target tissue to the second region and delivers the substance, the elastic sheath (12) contracts to maintain the injection pressure between the syringe (2) and the needle (3) higher than the pressure in the second region, so that at least a portion of the substance is discharged from the potential gap cavity (16) and delivered to the second region.

4. A syringe adapter (1) according to claim 3, characterized in that, The first region of the target tissue has a first density; and the second region of the target tissue has a second density, wherein the first density is higher than the second density.

5. A syringe adapter (1) according to claim 3 or 4, characterized in that, The first region of the target tissue generates a first back pressure on the needle tip (311) of the needle (3); The second region of the target tissue generates a second back pressure on the needle tip (311) of the needle (3), wherein the first back pressure is higher than the second back pressure.

6. A syringe adapter (1) according to any one of claims 3-5, characterized in that, The pressure threshold of the expansion of the elastic sheath (12) is not higher than the first back pressure and not lower than the second back pressure.

7. A syringe adapter (1) according to any one of claims 3-6, characterized in that, The target tissue is the eye; the first region is the sclera of the eye; and the second region is the space above the choroid of the eye.

8. A syringe adapter (1) according to claim 1, characterized in that, The syringe adapter (1) is used to connect the syringe (2) and the needle (3). When the needle tip (311) of the needle (3) is located in the suprachoroidal space, the injection pressure generated in the syringe (2) is insufficient to expand the elastic sheath (12), so that at least a portion of the substance in the syringe (2) is output through the needle (3); When the needle tip (311) is located within the sclera, the injection pressure generated by the syringe (2) is sufficient to inflate the elastic sheath (12), and the potential gap cavity (16) receives at least a portion of the substance delivered from the syringe (2) through the through channel (15), so that the substance in the syringe (2) cannot be output from the needle (3).

9. A syringe adapter (1) according to claim 1, characterized in that, The syringe adapter (1) is used to connect the syringe (2) and the needle (3). The elastic sheath (12) can switch between a first configuration and a second configuration. When the needle tip (311) of the needle (3) is located in the suprachoroidal space, the elastic sheath (12) is in a first configuration, so that at least a portion of the substance in the syringe (2) can be output through the needle (3); When the needle tip (311) is located within the sclera, the elastic sheath (12) is in a second configuration, and the potential gap cavity (16) receives at least a portion of the substance delivered from the syringe (2) through the through channel (15), such that the substance in the syringe (2) cannot be output from the needle (3).

10. A syringe adapter (1) according to any one of claims 1-9, characterized in that, The connector (11) is provided with a transparent viewing window, and / or the connector (11) is a transparent material component, and / or the outer wall of the elastic sheath (12) is provided with a conspicuous layer (17), and / or the syringe adapter (1) is provided with a touch sensor (18) for emitting a recognizable signal.

11. The syringe adapter (1) according to any one of claims 1-10, characterized in that, The syringe adapter (1) is used to connect the needle (3), and the expansion of the elastic sheath (12) allows the needle tip (311) of the needle (3) to extend into the suprachoroidal space. And / or, the contraction of the elastic sheath (12) can cause the needle tip (311) to contract toward the sclera.

12. A syringe adapter (1) according to claim 11, characterized in that, A flexible bottom (133) is provided at the distal end (111) of the connector (11), and / or a fluid-sealed cavity (134) is provided between the connector (11) and the needle (3), and / or a traction member (135) is provided in the region of the cavity (13) and the cavity (134).

13. An injection assembly, characterized in that, Including the syringe adapter (1) as described in claim 1, A syringe (2), the distal end of which is connected to the syringe adapter (1); and Needle (3), which is connected to the distal end of the syringe adapter (1); The syringe (2) and the needle (3) are fluidly connected via the syringe adapter (1).

14. An injection assembly according to claim 13, characterized in that, The syringe (2) includes a plunger (22), the distal end (222) of which is housed within the syringe (2), and the plunger (22) is configured to be subjected to force at its proximal end 221; wherein the syringe adapter (1), the syringe (2), and the needle (3) are configured such that: (1) When the needle tip (311) of the needle (3) is located in the second region of the target tissue and the injection pressure between the syringe (2) and the needle (3) is higher than the pressure threshold of the expansion of the elastic sheath (12), the elastic sheath (12) expands, thereby opening the potential gap cavity (16) to receive at least a portion of the substance delivered from the syringe (2) and reducing the injection pressure between the syringe (2) and the needle (3); (2) When the needle tip (311) of the needle (3) is located in the second region of the target tissue, and the injection pressure between the syringe (2) and the needle (3) is lower than the pressure threshold of the expansion of the elastic sheath (12), the elastic sheath (12) closes the potential gap cavity (16), so that at least a portion of the substance in the syringe (2) is output through the needle (3); (3) When the needle tip (311) of the needle (3) is located in the first region of the target tissue, and the injection pressure between the syringe (2) and the needle (3) is higher than the pressure threshold of the expansion of the elastic sheath (12), the elastic sheath (12) expands, thereby opening the potential gap cavity (16) to receive at least a portion of the substance delivered from the syringe (2), reducing the injection pressure between the syringe (2) and the needle (3) so that the substance in the syringe (2) cannot be output from the needle (3); (4) When the needle tip (311) of the needle (3) extends from the first region of the target tissue to the second region and delivers the substance, the elastic sheath (12) contracts to maintain the injection pressure between the syringe (2) and the needle (3) higher than the pressure in the second region, so that at least a portion of the substance is discharged from the potential gap cavity (16) and delivered to the second region.

15. An injection assembly according to claim 14, characterized in that, The first region of the target tissue has a first density; and the second region of the target tissue has a second density, wherein the first density is higher than the second density.

16. An injection assembly according to claim 14 or 15, characterized in that, The first region of the target tissue generates a first back pressure on the needle tip (311) of the needle 3; and the second region of the target tissue generates a second back pressure on the needle tip (311) of the needle 3, wherein the first back pressure is higher than the second back pressure.

17. An injection assembly according to any one of claims 14-16, wherein the pressure threshold of the expansion of the elastic sheath (12) is not higher than a first back pressure and not lower than a second back pressure.

18. An injection assembly according to any one of claims 14-17, characterized in that, The target tissue is the eye; the first region is the sclera of the eye; and the second region is the space above the choroid of the eye.

19. An injection assembly according to claims 14-18, characterized in that, The needle (3) includes a needle tube (31), a sleeve (33), an elastic element (34), and a needle seat (32); The proximal end (334) of the sleeve is connected to the syringe adapter (1), the needle hub (32) is sleeved inside the sleeve (33), and an elastic element (34) is provided between the proximal end (334) of the sleeve and the needle hub (32). The needle tube is mounted on the needle hub (32), and at least a portion of the needle tube is exposed in the sleeve (33); The elastic element (34) is configured to drive the sleeve (33) to move toward the proximal end (112) of the connector when deformed under pressure, thereby further extending the length of the needle tube protruding from the sleeve (33).

20. An injection assembly, characterized in that, The syringe adapter (1) according to any one of claims 1-10 is provided with an air vent (19) in the chamber (13); A syringe (2) with a through hole (23) on the syringe barrel wall (28) is connected to the syringe adapter (1) at its distal end. A housing (24) is sealed on the syringe (2), and the housing (24) allows fluid to flow between the syringe (2) and the chamber (13) through the through hole (23) and the air hole (19); The needle (3) includes a needle tube, a sleeve (33) fitted onto the distal end (111) of the connector (11), and a needle seat (32) fitted into the cavity (134). The distal end (142) of the catheter (14) is always kept in the needle seat (32) and is in fluid connection with the needle tube. The syringe (2) is provided with a piston assembly (25), which moves axially within the syringe (2) and can compress at least a portion of the air within the syringe (2), allowing at least a portion of the air within the syringe (2) to enter the chamber (13) and drive the needle seat (32) to move within the sleeve (33).

21. The injection assembly according to claim 20, characterized in that, The syringe (2) is provided with a push rod (22), which is used to drive the piston assembly (25) to move; The piston assembly (25) includes a first piston (251) and a second piston (252) disposed separately from each other. The first piston (251) contacts the push rod (22). The first piston (251) is used to compress the air in the syringe (2) so that at least a portion of the air in the syringe (2) enters the chamber (13), thereby driving the needle seat (32) to move within the sleeve (33). The second piston (252) is stationary before the first piston (251) contacts the second piston (252).

22. The injection assembly according to claim 21, characterized in that, When the needle tip (311) of the needle (3) is located inside the sclera, the first piston (251) can block the through hole (23).

23. The injection assembly according to claim 21, characterized in that, The syringe (2) has an anti-retraction part (26) on its inner wall. When the first piston (251) blocks the through hole (23), it contacts the anti-retraction part (26). The anti-retraction part (26) is used to ensure that the first piston (251) in contact with it can only move in the syringe (2) in the direction toward the distal end of the syringe (2).

24. An injection assembly according to claim 21, characterized in that, The syringe (2) is provided with a push rod (22), which is used to drive the piston assembly (25) to move; A flexible bottom (133) is provided at the distal end (111) of the connector (11), and / or a cavity (134) is provided between the connector (11) and the needle (3), and / or a traction component (135) is provided in the area of ​​the cavity (13) and the cavity (134). When the needle tip (311) of the needle (3) is not in contact with the eye tissue, the push rod (22) can drive the piston assembly (25) to move inside the syringe (2), so that at least a portion of the air inside the syringe (2) enters the housing (24) through the through hole (23) and enters the chamber (13), driving the needle seat (32) to move inside the sleeve (33), driving the needle tip (311) to move towards the distal end of the sleeve (33), so that the needle tip (311) is inserted into the eye tissue; When the needle tip (311) is located in the sclera, the injection pressure generated by the syringe (2) causes the elastic sheath (12) to expand, compressing the air in the syringe adapter (1), pushing the needle seat (32) to move toward the distal end of the needle (3), and causing the needle tip (311) to extend toward the suprachoroidal space. When the needle tip (311) is located in the suprachoroidal space to release the substance, the elastic sheath (12) retracts elastically, and the flexible bottom (133), the cavity (134), or the traction component (135) moves the needle seat (32) toward the distal end (111) of the connector (11), causing the needle tip (311) to retract.

25. An injection assembly, characterized in that, Including the syringe adapter (1) according to any one of claims 1-10, A syringe (2) has a through hole (23) in the syringe barrel wall (28) of the syringe (2), and the distal end of the syringe (2) is connected to the syringe adapter (1); A needle (3) is connected to the distal end of the syringe adapter (1); the needle (3) includes a needle tube, a sleeve (33), an air bladder (35), and a needle hub (32), the proximal end of the sleeve (33) being connected to the distal end (111) of the connector (11); and The housing (24) is fitted onto the syringe adapter (1). A through hole (36) is provided on the wall near the end of the sleeve (33) to allow air to pass between the housing (24) and the airbag (35). The housing (24) allows air to pass between the syringe (2) and the airbag (35) through the through hole (23) and the through hole (36). The syringe (2) is provided with a piston assembly (25), which can compress at least a portion of the air in the syringe (2) so that at least a portion of the air in the syringe (2) enters the airbag (35) and drives the needle seat (32) to move within the sleeve (33).

26. An injection assembly according to claim 25, characterized in that, The syringe (2) is provided with a push rod (22), which is used to drive the piston assembly (25) to move. When the needle tip (311) of the needle tube is not in contact with the eye tissue, the push rod (22) can drive the piston assembly (25) to move inside the syringe (2), so that at least a portion of the air inside the syringe (2) enters the airbag (35) through the through hole (23), drives the needle seat (32) to move inside the sleeve (33), and drives the needle tip (311) to move toward the distal end of the sleeve (33), so that the needle tip (311) is inserted into the eye tissue; When the needle tip (311) is located in the sclera, the elastic sheath (12) expands, allowing at least a portion of the air in the second chamber (132) of the cavity (13) to enter the airbag (35), causing the needle hub (32) to move toward the distal end (333) of the sleeve (33), and driving the needle tip (311) to extend toward the suprachoroidal space; When the needle tip (311) is located in the suprachoroidal space, the elastic sheath (12) retracts elastically, the second chamber (132) of the chamber (13) draws air from the airbag (35), and the needle seat (32) moves toward the distal end (111) of the connector (11), causing the needle tip (311) to retract.

27. The injection assembly according to claim 28, characterized in that, The syringe (2) is provided with a push rod (22), which is used to drive the piston assembly (25) to move; The piston assembly (25) includes a first piston (251) and a second piston (252) disposed separately from each other. The first piston (251) contacts the push rod (22). The first piston (251) is used to compress the air in the syringe (2) so that at least a portion of the air in the syringe (2) enters the chamber (13), thereby driving the needle seat (32) to move towards the distal end (333) of the sleeve (33). The second piston (252) is stationary before the first piston (251) contacts the second piston (252).

28. The injection assembly according to any one of claims 14-27, characterized in that, The distal end (333) of the sleeve (33) and / or the distal end of the needle seat (32) are provided with a clamping port (331), the clamping port (331) being configured to contact and press the eye tissue, causing the eye tissue within the clamping port (331) to protrude into the sleeve (33).

29. The injection assembly according to any one of claims 14-27, characterized in that, The distal end face of the sleeve (333) and / or the distal end face of the needle hub (32) is formed as a convex surface (332), which is configured to form a concave region in the ocular tissue that contacts the sleeve (33) and / or the needle hub (32), thereby forming a fluid seal when the distal end face of the sleeve (333) and / or the distal end face of the needle hub (32) contacts the ocular tissue.

30. The injection assembly according to any one of claims 14-27, characterized in that, A seal (27) is provided between the syringe (2) and the syringe adapter (1), and / or a sealing member (37) is provided between the syringe adapter (1) and the needle (3).

31. The method of using the syringe adapter (1) according to any one of claims 1-10, characterized in that, Includes the following steps: S1. The proximal end of the connector (11) is abutted against the distal end of the syringe (2), the syringe (2) including a push rod (22) which is capable of moving the substance inside the syringe (2); The distal end (111) of the connector (11) is abutted against the needle (3), the needle (3) including the needle tip (311), the needle tip (311) serving as the delivery outlet for the substance inside the syringe (2); This enables fluid connection between the syringe adapter (1), the syringe (2), and the needle (3); S2. When the distal surface of the needle (3) contacts the target tissue, a force is applied to the push rod (22) such that: When the needle tip (311) is located in the suprachoroidal space, the injection pressure generated in the syringe (2) is insufficient to cause the elastic sheath (12) to expand and disengage from the wall of the catheter (14), the elastic sheath (12) is in the first configuration, and at least a portion of the substance in the syringe (2) is output through the needle (3); When the needle tip (311) is located within the sclera, the injection pressure generated in the syringe (2) is sufficient to cause the elastic sheath (12) to expand and disengage from the wall of the catheter (14), the elastic sheath (12) changes from the first configuration to the second configuration, at least a portion of the substance delivered by the syringe (2) is discharged into the potential gap cavity (16) through the through channel (15), and the substance in the syringe (2) cannot be output from the needle (3); S3. When the elastic sheath (12) is found to be inflated, further force is applied directly or indirectly to the needle (3), so that the target tissue in contact with the needle (3) is further compressed, and the needle tip (311) extends from the sclera to the suprachoroidal space. S4. When the needle tip (311) extends from the sclera to the suprachoroidal space, at least a portion of the substance in the needle tip (311) is released, thereby reducing the injection pressure in the syringe (2); S5. When the injection pressure in the syringe (2) is reduced to a level insufficient to resist the elastic force of the elastic sheath (12), the elastic sheath (12) elastically retracts and adheres to the wall of the catheter (14), and the elastic sheath (12) changes from the second configuration to the first configuration, forcing the material in the potential gap cavity (16) to be discharged into the catheter (14) through the through channel (15) and delivered to the suprachoroidal space through the needle (3).

32. The method of using the syringe adapter (1) according to any one of claims 1-10, characterized in that, Includes the following steps: S1. The proximal end of the connector (11) is abutted against the distal end of the syringe (2), the syringe (2) including a push rod (22) which is capable of moving the substance inside the syringe (2); The distal end (111) of the connector (11) is abutted against the needle (3), the needle (3) including the needle tip (311), the needle tip (311) serving as the delivery outlet for the substance inside the syringe (2); This enables fluid connection between the syringe adapter (1), the syringe (2), and the needle (3); S2. When the distal surface of the needle (3) comes into contact with the ocular tissue, force is applied to the push rod (22): When the needle tip (311) of the needle (3) is located in the suprachoroidal space, if the injection pressure between the syringe (2) and the needle (3) is higher than the pressure threshold of the expansion of the elastic sheath (12), the elastic sheath (12) expands, changes from the first configuration to the second configuration, opens the potential gap cavity (16) to receive at least a portion of the substance delivered from the syringe (2), and reduces the injection pressure; When the needle tip (311) of the needle (3) is located in the suprachoroidal cavity, if the injection pressure between the syringe (2) and the needle (3) is lower than the pressure threshold of the expansion of the elastic sheath (12), the elastic sheath (12) is in the first configuration, closing the potential gap cavity (16), and at least a portion of the substance in the syringe (2) is output through the needle (3). When the needle tip (311) of the needle (3) is located in the sclera, if the injection pressure between the syringe (2) and the needle (3) is higher than the pressure threshold of the expansion of the elastic sheath (12), the elastic sheath (12) expands, changes from the first configuration to the second configuration, opens the potential gap cavity (16) to receive at least a portion of the substance delivered from the syringe (2), reduces the injection pressure, and prevents the substance in the syringe (2) from being output from the needle (3); When the needle tip (311) of the needle (3) extends from the sclera to the suprachoroidal space and delivers the substance, the injection pressure between the syringe (2) and the needle (3) decreases, and the elastic sheath (12) contracts, changing from the second configuration to the first configuration, so as to maintain the injection pressure between the syringe (2) and the needle (3) higher than the pressure in the suprachoroidal space, so that at least a portion of the substance is discharged from the potential gap cavity (16) and delivered to the suprachoroidal space.

33. The method of using the syringe adapter (1) according to claim 13, characterized in that, Includes the following steps: S1. The proximal end of the connector (11) is abutted against the distal end of the syringe (2), the syringe (2) including a push rod (22) which can push the fluid inside the syringe (2) to move; The distal end (111) of the connector (11) is abutted against the needle (3), the needle (3) including the needle tip (311), the needle tip (311) serving as the delivery outlet for the substance inside the syringe (2); To achieve fluid connection between the syringe adapter (1), the syringe (2), and the needle (3); S2. When the needle tip (311) of the needle (3) comes into contact with the target tissue, force is applied to the push rod (22): When the needle tip (311) is located in the suprachoroidal space, the injection pressure generated in the syringe (2) is insufficient to cause the elastic sheath (12) to expand and disengage from the wall of the catheter (14), the elastic sheath (12) is in the first configuration, and at least a portion of the substance in the syringe (2) is output through the needle (3); When the needle tip (311) is located within the sclera, the injection pressure generated in the syringe (2) is sufficient to cause the elastic sheath (12) to expand and disengage from the catheter wall (141) of the catheter (14), the elastic sheath (12) changes from the first configuration to the second configuration, at least a portion of the substance delivered by the syringe (2) is discharged into the potential gap cavity (16) through the through channel (15), and the substance in the syringe (2) cannot be output from the needle (3); When the elastic sheath (12) is converted from the first configuration to the second configuration, the gas outside the elastic sheath in the chamber (13) is pressurized, causing the needle seat (32) to move toward the distal end (111) of the connector (11), thereby driving the needle tip (311) to extend further into the suprachoroidal space. S3. When the needle tip (311) extends and reaches the suprachoroidal space, the elastic sheath (12) changes from the second configuration to the first configuration, and at least a portion of the material in the potential gap cavity (16) is discharged into the catheter (14) through the through channel (15) and delivered to the suprachoroidal space via the needle tip (311); When the elastic sheath (12) changes from the second configuration to the first configuration, the cavity (134), the flexible bottom (133), or the traction component (135) recovers and contracts, causing the needle tip (311) to gradually retract.

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