Spring-based vitreous cavity injector based on intraocular pressure feedback

Abstract

This invention discloses a spring-loaded intraocular syringe based on intraocular pressure feedback, belonging to the field of medical devices. The core improvement of this device lies in the integration of an integrated spring mechanism at the syringe outlet interface. Its main structure is a hollow cylindrical structure forming a three-way connection with the syringe outlet interface. A sealing septum divides the inner cavity of the main structure into a non-communicating medication chamber and a spring chamber. During injection, the intraocular pressure is transmitted to the sealing septum through the medication. When the pressure exceeds the spring's preset preload, the spring is compressed, causing the sealing septum to displace. When this displacement reaches a preset safe intraocular pressure threshold, it triggers a visually intuitive stop signal, objectively and accurately prompting the operator to stop the injection. This invention achieves automatic matching control of the injection volume and intraocular pressure through a mechanical pressure feedback mechanism, reducing reliance on operator experience and improving the safety and precision of surgical procedures, making it particularly suitable for primary healthcare settings.

Description

Technical Field

[0001] This invention belongs to the field of medical devices, specifically relating to a spring-loaded intravitreal injector based on intraocular pressure feedback. Background Technology

[0002] Intravitreal injection is a core treatment for age-related macular degeneration, diabetic macular edema, and other retinal diseases. This procedure involves directly injecting medication (such as anti-VEGF drugs) into the vitreous cavity to achieve high concentrations of the drug in the target tissue. However, the procedure carries clear risks: excessive injection volume can lead to a sharp increase in intraocular pressure (IOP), potentially damaging the optic nerve; insufficient injection affects efficacy and wastes expensive medication. Currently, dosage control relies entirely on the surgeon's subjective judgment based on feel, which demands a high level of experience. The risks are particularly pronounced in primary care hospitals or when performed by less experienced medical personnel. Post-injection fluctuations in intraocular pressure are common in clinical practice, making precise and safe dosage control a pressing issue that needs to be addressed.

[0003] Existing technologies include some automated injection devices, such as auto-injectors (CN110662569A) that use compression springs to provide injection power. However, these devices primarily aim to automatically advance the medication and do not address the safety control issue of real-time matching of injection volume with intraocular pressure. Therefore, there is an urgent need for a device that can objectively reflect changes in intraocular pressure and alert the operator to stop the injection. Summary of the Invention

[0004] The purpose of this invention is to overcome the deficiencies in the prior art and provide a spring-loaded intraocular injector based on intraocular pressure feedback. This injector converts the increase in intraocular pressure into mechanical displacement and provides a clear signal when a safe threshold is reached, thereby assisting operators of any skill level to safely and accurately complete injections.

[0005] The specific technical solution adopted in this invention is as follows: This invention provides a spring-loaded intravitreal syringe based on intraocular pressure feedback, comprising a piston rod, a syringe barrel, and a needle, wherein the syringe barrel and the needle are connected through a syringe barrel outlet interface; an integrated spring device is provided on one side of the syringe barrel outlet interface; The integrated spring device includes a main structure, a sealing partition, a spring, and a spring cover. The main structure is a tubular structure, with one end connected to the side wall of the syringe outlet interface and the inner wall slidably sealed with a sealing partition. The other end is provided with an internal thread for screwing onto the spring cover. The sealing partition divides the inner cavity of the main structure into a liquid cavity near the syringe and a spring cavity near the spring cover. One end of the spring abuts against the back of the sealing partition, and the other end abuts against the spring cover. By adjusting the spring's stiffness coefficient, the pressure at which it is compressed and displaced is set to match the normal intraocular pressure threshold. This ensures that once the drug is injected to the set intraocular pressure threshold, the spring is compressed, the sealing septum moves, and a signal to stop the injection is given.

[0006] Preferably, the piston rod includes a push rod and a piston head; one end of the push rod is located outside the syringe barrel, and the other end is connected to the piston head; the piston head is made of an elastic material and is slidably and sealingly connected to the inner wall of the syringe barrel.

[0007] Preferably, the syringe includes a syringe flange and a syringe body; the top of the syringe body is provided with a syringe flange that is easy to hold and apply force to, and the syringe body is made of transparent or semi-transparent material and is marked with capacity scale along the axial direction.

[0008] Preferably, the needle includes a needle hub, a bevel, a needle tube, and a protective sleeve; the needle hub is circumferentially sealed to the bottom of the syringe outlet interface, the bottom is connected to the needle tube through a gradually narrowing bevel, and the needle tube is detachably covered with a protective sleeve.

[0009] Preferably, the inner cavity of the syringe outlet interface adopts a tapered structure that gradually decreases from top to bottom or a Luer connector.

[0010] Preferably, the end of the main structure connected to the syringe outlet interface is provided with a limiting structure to prevent the sealing diaphragm from entering the inner cavity of the syringe outlet interface.

[0011] Preferably, the main structure has a transparent tube wall for observing the sliding position of the sealing septum. The transparent tube wall is marked with indicators for safe and warning zones according to their positions. The sealing septum is fixed with color marks for observation. The position of the color mark in the safe or warning zone is used to determine the intraocular pressure and provide visual cues.

[0012] Preferably, the sealing septum is provided with an elastic buckle that can extend and retract radially on its side, and a slot for embedding the elastic buckle is provided at the preset displacement endpoint of the inner wall of the main structure; when the sealing septum moves to the slot under the action of intraocular pressure, the elastic buckle can enter the slot to prevent the sealing septum from moving, and provide tactile and / or auditory feedback.

[0013] Preferably, the initial position of the sealing septum is adjacent to the end wall of the injection cylinder outlet interface.

[0014] Preferably, the main structure wall is provided with pressure indication scale along the axial direction.

[0015] Compared with the prior art, the present invention has the following advantages: (1) Active safety protection: The intraocular pressure safety threshold is materialized through mechanical structure to prevent over-injection due to operational negligence or misjudgment, thus fundamentally avoiding the risk of iatrogenic hyperocular pressure.

[0016] (2) Strong operational universality: It provides objective stop signals that do not require experience to interpret, which greatly reduces the operational threshold and enables the technology to be safely applied in a wider range of medical scenarios (including primary hospitals).

[0017] (3) Precise dosage: Ensure that each injection reaches the effective therapeutic pressure window, avoid insufficient injection due to premature cessation, and ensure the therapeutic effect.

[0018] (4) Personalized adaptation: The spring preload is adjustable, which can flexibly adapt to different patient groups from low intraocular pressure to high intraocular pressure, and realize individualized safe injection.

[0019] (5) Compact and reliable structure: The integrated design requires no external circuits or sensors, has low cost and high reliability, and is suitable for production as a disposable medical consumable. Attached Figure Description

[0020] Figure 1 This is a schematic cross-sectional view of the overall structure of a spring-loaded intraocular injector based on intraocular pressure feedback; Figure 2 This is a partially enlarged cross-sectional view (visual cues) of an integrated spring device in a spring-loaded intraocular injector based on intraocular pressure feedback. Figure 3 This is a partially enlarged cross-sectional view of an integrated spring device in a spring-loaded intravitreal injector based on intraocular pressure feedback (tactile / auditory cues). The attached figures are labeled as follows: piston rod 1, push rod 11, piston head 12, syringe 2, syringe flange 21, syringe body 22, syringe outlet interface 23, needle 3, needle seat 31, inclined surface 32, needle tube 33, protective sleeve 34, integrated spring device 4, main structure 41, sealing diaphragm 42, spring 43, spring cover 44, elastic buckle 45, and slot 46. Detailed Implementation

[0021] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below. Technical features in various embodiments of the present invention can be combined accordingly without mutual conflict.

[0022] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0023] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0024] like Figure 1 As shown, this invention provides a spring-loaded intravitreal syringe based on intraocular pressure feedback. In addition to the conventionally configured piston rod 1, syringe barrel 2, and needle 3, the syringe innovatively incorporates an integrated spring device 4. The syringe barrel 2 and needle 3 are connected via a syringe barrel outlet interface 23, and the integrated spring device 4 is fixedly connected to one side of the syringe barrel outlet interface 23. The syringe barrel outlet interface 23 and the integrated spring device 4 together form a T-shaped tubing section.

[0025] In a preferred embodiment of the present invention, the piston rod 1 mainly includes a push rod 11 and a piston head 12. One end of the push rod 11 is located outside the syringe 2, and the other end is connected to the piston head 12 and located inside the syringe 2. The piston head 12 is made of an elastic material (such as medical rubber or silicone) and forms a sliding seal connection with the inner wall of the syringe 2 for drawing and pushing the liquid medicine.

[0026] In a preferred embodiment of the present invention, the syringe 2 mainly includes a syringe flange 21 and a syringe body 22. The syringe flange 21 is provided circumferentially outward at the top of the syringe body 22, facilitating grip and force application by the operator. The syringe body 22 is cylindrical, used to hold the liquid medicine, and is made of transparent or semi-transparent material. It is also marked with volume graduations along the axial direction for measuring the volume of the liquid medicine.

[0027] In a preferred embodiment of the present invention, the needle 3 includes a needle base 31, a bevel 32, a needle tube 33, and a protective sleeve 34. The needle base 31 is circumferentially sealed to the bottom of the syringe outlet interface 23, and its structure is a tapered shape or other matching structure (such as a Luer lock) with the same inner diameter as the outer diameter of the syringe outlet interface 23 to ensure its sealing performance. At the same time, the upper edge of the needle base 31 should be located below the integrated spring device 4. The bottom of the needle base 31 is connected to the needle tube 33 through the gradually narrowing bevel 32, and the needle tube 33 is detachably fitted with a protective sleeve 34.

[0028] As a preferred embodiment of the present invention, both the syringe outlet interface 23 and the needle seat 31 can adopt a tapered structure with an inner diameter that gradually decreases from top to bottom (such as a standard Luer cone) to achieve a fast and reliable connection.

[0029] In the syringe of the present invention, the integrated spring device 4 mainly includes a main body structure 41, a sealing septum 42, a spring 43 and a spring cover 44. It uses a mechanical structure to convert hydraulic changes in the vitreous cavity into a perceptible physical signal with a lower manufacturing cost.

[0030] Specifically, the main structure 41 is a tubular structure, with one end connected to the side wall of the syringe outlet interface 23. A sealing partition 42 is slidably sealed to the inner wall of this end. The other end of the main structure 41 has an internal thread for screwing onto the spring cover 44. One end of the spring 43 abuts against the back of the sealing partition 42, and the other end abuts against the spring cover 44. The sealing partition 42 divides the inner cavity of the main structure 41 into a liquid cavity near the syringe 2 and a spring cavity near the spring cover 44; the two chambers are not interconnected. The liquid cavity is connected to the syringe outlet interface 23, while the spring cavity houses the spring 43.

[0031] In actual use, by adjusting the spring constant of spring 43, the pressure at which it is compressed and displaced is set to match the normal intraocular pressure threshold, so that after the drug is injected to the set intraocular pressure threshold, spring 43 is compressed, sealing septum 42 moves, and a signal to stop injection is given.

[0032] In a preferred embodiment of the present invention, the spring cap 44 is screwed into the end of the main body structure 41 to close the spring cavity and limit the end of the spring 43. For easy and precise adjustment and calibration, a pressure scale can be provided on the main body structure 41.

[0033] As a preferred embodiment of the present invention, the end of the main structure 41 connected to the injection barrel outlet interface 23 is provided with a limiting structure (such as a circumferential protrusion) to prevent the sealing diaphragm 42 from entering the inner cavity of the injection barrel outlet interface 23.

[0034] As a preferred embodiment of the present invention, the main structure 41 is a hollow column, and its outer diameter should be smaller than the distance between the lower edge of the syringe barrel body 22 and the upper edge of the needle seat 31. At the same time, the angle between this structure and the syringe barrel outlet interface 23 can be any angle.

[0035] In a preferred embodiment of the present invention, the outer diameter of the spring cover 44 is the same as the inner diameter of the main body structure 44, and it is connected to the outermost edge of the main body structure 44 by threads. The two are flush with each other, ensuring that they will not be displaced due to changes in the pressure inside the injection cylinder, while ensuring good overall sealing performance of the integrated spring device 4.

[0036] In a preferred embodiment of the present invention, the sealing septum 42 is made of medical-grade silicone or rubber, and its outer edge forms a tight sliding seal with the inner wall of the main structure 41. The main structure 41 may be made of transparent medical plastic (such as polycarbonate).

[0037] In a preferred embodiment of the present invention, the initial elastic force can be set by adjusting the properties of the spring 43 according to the intraocular pressure requirement. In the initial (uncompressed) state, the sealing septum 42 is designed to be approximately flush with the end wall of the syringe outlet interface 23, so as to minimize the volume of liquid entering the liquid chamber of the integrated spring device 4, thereby reducing the waste of expensive therapeutic drugs.

[0038] In practical use, the coordinated action of the aforementioned components enables a clear stop injection signal to be provided once the intraocular pressure reaches a preset value during the injection process, assisting operators of any skill level to complete the injection safely and accurately. In other words, when the intraocular pressure reaches the preset threshold, the stop signal is triggered by the displacement of the sealing septum 42. This signal can be implemented in the following way: Visual cues: such as Figure 2 As shown, the main structure 41 has a transparent tube wall with indicator marks for safe and warning zones, and a color mark (such as a red ring) is fixed on the sealing septum 42. Initially, the color mark is located at the beginning of the observation window (such as a green ring). When injection causes an increase in intraocular pressure, the spring 43 is compressed, and the sealing septum 42 moves the color mark towards the spring cover 44. Once the color mark moves to the preset warning zone (such as the red ring), it indicates that the intraocular pressure has reached the safe upper limit, and the operator should immediately stop the injection.

[0039] Tactile and / or auditory cues: such as Figure 3 As shown, an elastic buckle 45 is provided on the side (e.g., circumferentially, on the top and bottom sides) of the movable sealing septum 42, and a slot 46 is provided at the corresponding displacement endpoint on the inner wall of the main structure 41. In the initial state, the buckle is slightly compressed by the inner wall of the main structure 41. When the intraocular pressure increases and pushes the sealing septum 42 to the threshold position, the elastic buckle 45 is exactly aligned with the slot 46, and quickly springs into the slot 46 under its own elastic force, producing a clear "click" sound and a distinct sensation, which is transmitted to the operator's finger through the syringe barrel, forming a clear tactile and auditory stop signal.

[0040] The operating principle of the syringe of this invention is as follows: When the needle enters the vitreous cavity and the medication is injected, the pressure inside the vitreous cavity rises. This pressure is transmitted through the main structure of the needle and integrated spring device to the movable sealing septum, creating a force opposite to the direction of medication injection. When this force exceeds the spring's preset preload, the spring begins to compress, and the movable sealing septum moves towards the end of the main structure. Once the spring is compressed to a preset threshold position (i.e., the intraocular pressure reaches the safe upper limit), a clear warning signal is triggered.

[0041] Utilizing the aforementioned spring-loaded intravitreal syringe based on intraocular pressure feedback, the present invention also provides a drug injection method, comprising the following steps: S1, Preoperative calibration steps: Based on the baseline intraocular pressure value of the patient to be treated, a mechanical trigger point corresponding to the patient's safe intraocular pressure threshold is set by adjusting the stiffness coefficient and the compressed displacement of the spring 43 of the integrated spring device 4 of the syringe of the present invention. S2, Injection Preparation Steps: The patient's eyes are disinfected and anesthetized. The treatment medication is drawn into a syringe and the needle is inserted into the vitreous cavity 3.5-4 mm behind the limbus of the eyeball. S3, Injection and Feedback Steps: The medication is injected slowly, while the operator closely monitors the feedback status of the integrated spring device 4 (observing the position of the movable sealing septum or sensing the trigger). When the injection causes the intravitreal pressure to rise to the safe intraocular pressure threshold, the spring 43 is compressed, the sealing septum 42 is displaced, and a stop signal is released. S4, Terminate injection procedure: Upon receiving a stop signal (observing a change in the position of the movable sealing septum, or feeling / hearing the vibration and sound of the latch snapping in), immediately stop pushing the piston rod 1 to complete the injection. At this point, the volume of medication injected into the vitreous cavity raises the intraocular pressure to the safe upper limit, thus ensuring the efficacy while maximizing surgical safety.

[0042] This invention achieves automatic matching control of injection volume and intraocular pressure through a mechanical pressure feedback mechanism, reducing reliance on operator experience and improving the safety and precision of surgical procedures, making it particularly suitable for primary healthcare settings.

[0043] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the invention. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, all technical solutions obtained through equivalent substitution or transformation fall within the protection scope of the present invention.

Claims

1. A spring-loaded intraocular pressure feedback-based intraocular syringe, comprising a piston rod (1), a syringe barrel (2), and a needle (3), characterized in that, The syringe (2) and the needle (3) are connected through the syringe outlet interface (23); an integrated spring device (4) is provided on one side of the syringe outlet interface (23). The integrated spring device (4) includes a main structure (41), a sealing diaphragm (42), a spring (43), and a spring cover (44). The main structure (41) is a tubular structure, with one end connected to the side wall of the syringe outlet interface (23) and the inner wall slidably sealed with the sealing diaphragm (42). The other end is provided with an internal thread for screwing with the spring cover (44). The sealing diaphragm (42) divides the inner cavity of the main structure (41) into a liquid cavity near the syringe (2) and a spring cavity near the spring cover (44). One end of the spring (43) abuts against the back of the sealing diaphragm (42), and the other end abuts against the spring cover (44). By adjusting the spring constant (43), the pressure at which it is compressed and displaced is set to match the normal intraocular pressure threshold, so that after the drug is injected to the set intraocular pressure threshold, the spring (43) is compressed, the sealing septum (42) moves, and a signal to stop the injection is given.

2. The spring-loaded intraocular syringe based on intraocular pressure feedback according to claim 1, characterized in that, The piston push rod (1) includes a push rod (11) and a piston head (12); one end of the push rod (11) is located outside the injection cylinder (2), and the other end is connected to the piston head (12); the piston head (12) is made of elastic material and is slidably sealed to the inner wall of the injection cylinder (2).

3. A spring-loaded intraocular syringe based on intraocular pressure feedback according to claim 1, characterized in that, The syringe (2) includes a syringe flange (21) and a syringe body (22); the top of the syringe body (22) is provided with a syringe flange (21) that is easy to hold and apply force to. The syringe body (22) is made of transparent or semi-transparent material and is marked with capacity scale along the axial direction.

4. A spring-loaded intraocular injection device based on intraocular pressure feedback according to claim 1, characterized in that, The needle (3) includes a needle seat (31), a bevel (32), a needle tube (33), and a protective sleeve (34); the needle seat (31) is circumferentially sealed to the bottom of the syringe outlet interface (23), and the bottom is connected to the needle tube (33) through a gradually narrowing bevel (32), and the needle tube (33) is provided with a detachable protective sleeve (34).

5. A spring-loaded intraocular syringe based on intraocular pressure feedback according to claim 1, characterized in that, The inner cavity of the syringe outlet interface (23) adopts a tapered structure or Luer connector that gradually decreases in size from top to bottom.

6. A spring-loaded intravitreal injector based on intraocular pressure feedback according to claim 1, characterized in that, The main structure (41) is provided with a limiting structure at one end connected to the syringe outlet interface (23) to prevent the sealing diaphragm (42) from entering the inner cavity of the syringe outlet interface (23).

7. A spring-loaded intraocular injection device based on intraocular pressure feedback according to claim 1, characterized in that, The main structure (41) has a transparent tube wall for observing the sliding position of the sealing septum (42). The tube wall is marked with indicators for safe and warning zones according to the position. The sealing septum (42) is fixed with color marks for observation. The position of the color mark in the safe or warning zone is used to determine the intraocular pressure.

8. A spring-loaded intraocular injection device based on intraocular pressure feedback according to claim 1, characterized in that, The sealing septum (42) has an elastic buckle (45) that can extend and retract radially on its side. The inner wall of the main structure (41) has a slot (46) for embedding the elastic buckle (45) at the preset displacement endpoint. When the sealing septum (42) moves to the slot (46) under the action of intraocular pressure, the elastic buckle (45) can enter the slot (46) to prevent the sealing septum (42) from moving and provide tactile and / or auditory feedback.

9. A spring-loaded intraocular syringe based on intraocular pressure feedback according to claim 1, characterized in that, The initial position of the sealing septum (42) is adjacent to the end wall of the syringe outlet port (23).

10. A spring-loaded intravitreal injector based on intraocular pressure feedback according to claim 1, characterized in that, The main structure (41) has pressure indicator scales along the axial direction on its wall surface.

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