A passive needle-puncture prevention device for syringes

Abstract

This invention discloses a passive needle-puncture prevention device for a syringe, comprising a pre-filled syringe, an outer shell, an inner shell, a push rod, and a spring. The pre-filled syringe is filled with medication and is fixed in the central cavity of the inner shell, with its front end extending outwards. The push rod is located at the rear end of the inner shell, propelling the medication into the pre-filled syringe. The rear end of the outer shell has symmetrical flange platforms extending to both sides, and a gripper along the axis of the outer shell is located on the flange platform, with the top of the gripper featuring an inwardly protruding protrusion. The entire device uses only five structural components, facilitating assembly and reducing costs. Furthermore, doctors can automatically retract the needle after injection without altering their usual operating habits, thus reducing unintended needle-puncture injuries.

Description

Technical Field

[0001] This invention belongs to the field of medical device injection technology, specifically relating to a passive anti-needle-puncture device for a syringe. Background Technology

[0002] A syringe is a common medical device, typically used for injecting drugs or drawing fluids. It can be used for a variety of purposes in medical, laboratory, and research fields. It is used to inject drugs to treat diseases, administer vaccines, or administer other medications. Furthermore, syringes can be used in laboratories to extract and analyze liquid samples, as well as for various experimental purposes in scientific research.

[0003] However, the proper use of syringes remains highly controversial. In 2023, the WHO estimated that there were as many as 3.35 million needlestick injuries globally each year, meaning one in ten healthcare workers would experience a needlestick injury annually. If the patient is hepatitis B virus positive, the risk of blood-borne transmission is approximately 30%; if the patient is hepatitis C virus positive, it is 4-5%; and if the patient is HIV positive, it is 0.3-0.5%. Even without transmission of infection, needlestick injuries can cause considerable psychological fear and stress. Chinese epidemiologists point out that the risk of infection from needle exposure depends on the prevalence of bloodborne infectious diseases in the population. Therefore, the current trend significantly increases the potential risk of bloodborne infection from sharps injuries.

[0004] In many cases, canceling the injection or using alternative administration methods is not feasible. Therefore, safety devices are the most effective solution for handling hazards. One type of safety device on the market is active, requiring additional action from the user after injection to activate the protection. Therefore, from a safer injection perspective, passive needle protection solutions are safer because active solutions rely on the operator performing an extra step, which depends on operator training and changes in existing injection practices. Passive needle protection is preferable because it requires almost no additional action and can activate automatically or with one hand.

[0005] Chinese patent application number 202211178831.9 discloses a rotating anti-needle-puncture syringe. After use, rotating the rotating latch unlocks the syringe, causing the inner shell to move the drug delivery component upwards. The rotating latch then locks with the lower slot, providing a good locking effect. Its main function is to prevent the injection needle from protruding, thus preventing puncture wounds to medical personnel and those recovering the syringe, and preventing the spread of pathogens. However, this device uses a separate and complex locking structure. During assembly, this structure requires separate locking and engagement, affecting the assembly process. Furthermore, during use, the rotating latch needs to be unlocked to allow the syringe containing the drug delivery component to spring back, increasing the cost for doctors. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to provide a passive anti-needle-puncture device for syringes, which solves the above-mentioned technical problems existing in the prior art.

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] A passive needle-puncture prevention device for a syringe includes a pre-loaded syringe, an outer shell, an inner shell, a plunger, and a spring.

[0009] The pre-filled syringe is filled with a drug and is fixed in the middle cavity of the inner shell, with the front end extending outward. A push rod is provided at the rear end of the inner shell to push the drug in the pre-filled syringe.

[0010] The rear end of the outer shell is provided with a flange platform that extends symmetrically to both sides, and a grab is provided on the flange platform along the axis of the outer shell. The top of the grab is provided as an inward protrusion.

[0011] An annular positioning element is provided at the rear end of the inner housing, and the annular positioning element and the locking element on the outer wall of the inner housing form a channel for the passage of the grabber, and is located at the bottom spring element of the inner housing.

[0012] When the push rod is pushed forward for injection, the protrusion on the outer shell forms a gripping lock on the locking member on the inner shell. After the pre-filled syringe is injected, the rear end of the push rod forms an outward squeeze on the locking member, thereby releasing the locking member on the inner shell from the gripping lock. Under the action of the bottom spring, the pre-filled syringe is simultaneously driven to rebound backward until the front tip of the pre-filled syringe is completely rebounded into the outer shell.

[0013] Furthermore, both the outer shell and the inner shell are constructed as a single piece.

[0014] Furthermore, a strip-shaped slot extending along the axial direction is provided through the outer wall of the outer shell, and an outwardly protruding limiting block is provided at the bottom of the inner shell, so that the movement area of ​​the limiting block is embedded in the area formed by the strip-shaped slot, thereby limiting the upward and downward position of the inner shell.

[0015] Furthermore, the strip-shaped slot is set at symmetrical positions on both sides of the outer shell, and two sets of limiting blocks for the inner shell are set simultaneously.

[0016] The strip-shaped slots are perpendicular to the direction in which the flange platform extends.

[0017] Furthermore, annular ribs are provided on the outer wall of the inner shell to cooperate with the inner wall of the outer shell, so as to ensure that the advancing direction of the inner shell is the same as the extension direction of the inner cavity of the outer shell.

[0018] Furthermore, a stop buckle is provided on the outer wall of the outer shell, so that the front end of the stop buckle protrudes into the inner side of the outer shell. When the inner shell is pushed forward along the circumferential direction of the inner cavity of the outer shell, the stop buckle limits the position of the annular rib located on the upper part of the outer wall of the inner shell.

[0019] Furthermore, the bottom of the fastening surface where the protrusion is located is set as an inwardly inclined slope structure, while the outer edge of the locking member located on the inner shell is set as an upwardly inclined slope, forming a locking engagement with the fastening surface of the protrusion.

[0020] Furthermore, the inward tilt angle of the protrusion is between 0 and 20°.

[0021] Furthermore, the rear end of the push rod is configured as a frustum, and the frustum is configured with two discs arranged vertically, with an annular groove between the two discs.

[0022] Furthermore, the upper end of the protrusion has an outwardly inclined slope structure, which allows for a smooth transition when the truncated cone of the push rod is pushed forward with the protrusion.

[0023] The beneficial effects of this invention are:

[0024] 1. When doctors perform injections using this device, the needle can automatically retract after the injection without changing their original operating habits, thereby reducing needle prick injuries that are not intended for the purpose and greatly improving safety and efficiency.

[0025] 2. This device uses fewer structural components, and both the inner and outer shells are integrally molded. In actual use, this reduces the number of times each component needs to be assembled, improves the assembly efficiency, ensures assembly accuracy, and reduces cost.

[0026] 3. The bottom of the fastening surface where the protrusion is located in this device is set as an inward inclined slope structure, and the outer edge of the locking member on the inner shell is set as an upward inclined slope, forming a locking engagement with the fastening surface of the protrusion, which can achieve locking and fixation and improve the reliability of fastening.

[0027] 4. The upper part of the protrusion of the grab used in this device is set at an angle. When the push rod is pushed in, the rear end forms a structure that opens to both sides of the protrusion. Automatic unlocking between the outer shell and the inner shell can be achieved without additional accessories. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0029] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present invention;

[0030] Figure 2 This is a schematic diagram of the rear end structure of an embodiment of the present invention;

[0031] Figure 3 This is a schematic diagram of the overall structure in the first cross-section of an embodiment of the present invention;

[0032] Figure 4 This is a schematic diagram of the overall outer shell of an embodiment of the present invention;

[0033] Figure 5 This is a schematic diagram of the inner shell of an embodiment of the present invention;

[0034] Figure 6 This is a schematic diagram of the overall structure in the second cross-section of an embodiment of the present invention;

[0035] Figure 7 This is an embodiment of the present invention. Figure 6 A partial structural diagram at point A in the middle;

[0036] Figure 8 This is a schematic diagram showing another state of the overall structure of an embodiment of the present invention;

[0037] Figure 9 This is an embodiment of the present invention. Figure 8 A partial structural diagram at point B in the middle.

[0038] Figure 10This is a schematic diagram of the cross-sectional structure of the pre-loaded syringe before its rebound, according to an embodiment of the present invention.

[0039] Figure 11 This is a schematic diagram of the cross-sectional structure of the pre-loaded syringe after rebound according to an embodiment of the present invention;

[0040] Figure 12 This is an embodiment of the present invention. Figure 11 A partial structural diagram at point C. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0042] like Figure 1 , Figure 2 As shown, this embodiment of the invention provides a passive anti-needle-puncture device for a syringe, including a pre-loaded syringe 1, an outer shell 2, an inner shell 3, a push rod 4, and a spring 5.

[0043] like Figure 3 As shown, the pre-filled syringe 1 is filled with a drug and is fixed in the middle cavity of the inner shell 3, with the tip of the front end extending downward (outward). A push rod 4 is provided at the rear end of the inner shell 3. The push rod 4 pushes the drug in the pre-filled syringe 1. The outer shell 2 forms a wrap around the outside of the inner shell 3.

[0044] like Figure 4 As shown, the rear end of the outer casing 2 is provided with symmetrical flange platforms 21 extending to both sides. A grabber 22 (extending rearward in this case) is provided on the flange platform 21 along the axis of the outer casing 2. The top of the grabber 22 is a protruding inward protrusion 23. Figure 8 , Figure 9 As shown, the protrusion 23 on the grabber 22 forms a grip on the rear end of the inner housing 3. The bottom of the engagement surface where the protrusion 23 is located is set as an inwardly inclined slope structure. At the same time, the outer edge of the locking member 32 on the inner housing 3 is set as an upwardly inclined slope, forming a locking engagement with the engagement surface of the protrusion 23. In order to better achieve the locking effect, the inwardly inclined slope angle of the protrusion 23 is between 1 and 20°.

[0045] like Figure 5 , Figure 6 , Figure 7As shown, an annular positioning member 31 is provided at the rear end of the inner housing 3. This annular positioning member 31 and the locking member 32 on the outer wall of the inner housing 3 form a channel for the passage of the grabber 22. A spring member 5 is located at the bottom of the inner housing 3, allowing the inner housing 3 to spring back. To ensure a firm connection between the inner housing 3 and the outer housing 2, symmetrical stop protrusions 24 are provided on opposite sides of the grabber 22. When the grabber 22 and the locking member 32 engage, the stop protrusions 24 simultaneously abut against the inner surface of the annular positioning member 31. This design allows for locking of the inner housing 3 and the outer housing 2 at multiple angles (i.e., four directions).

[0046] Meanwhile, annular ribs 302 are provided on the outer wall of the inner shell 3 to cooperate with the inner wall of the outer shell 2, so that the annular ribs 302 fit against the inner wall of the outer shell 2, thereby ensuring that the advancing direction of the inner shell 3 is the same as the extension direction of the inner cavity of the outer shell 2.

[0047] To reduce costs and facilitate assembly, both the outer shell 2 and the inner shell 3 are designed as a single piece. This reduces the number of parts required for assembly and simultaneously increases the overall installation speed.

[0048] A strip-shaped slot 201 extending along the axial direction is provided through the outer wall of the outer shell 2. Simultaneously, a limiting block 301 protruding outward is provided at the bottom of the inner shell 3. The moving area of ​​the limiting block 301 is embedded within the area formed by the strip-shaped slot 201 (i.e., the limiting block 301 protrudes outward from the area of ​​the strip-shaped slot 201), thus limiting the upward and downward movement of the inner shell 3. To improve the stability of the push between the outer shell 2 and the inner shell 3, the strip-shaped slot 201 is positioned symmetrically on both sides of the outer shell 2. Two sets of limiting blocks 301 are simultaneously provided for the inner shell 3 to prevent shaking during push and ensure relative stability during advancement or rebound.

[0049] A stop latch 202 is provided on the outer wall of the outer shell 2, with the front end of the stop latch 202 protruding inward from the outer shell 2. When the inner shell 3 is pushed forward along the circumferential direction of the inner cavity of the outer shell 2, the stop latch 202 limits the position of the annular rib 302 located on the upper part of the outer wall of the inner shell 3. That is, when the inner shell 3 moves downward relative to the outer shell 2, the annular rib 302 on the inner shell 3 will block the stop latch 202 on the outer shell 2, but when the inner shell 3 springs back, the annular rib 302 will not block the stop latch 202.

[0050] The rear end of the push rod 4 is configured as a frustum 41, which consists of two discs arranged vertically. An annular groove 401 is positioned between the two discs to separate the two frustum 41. The upper end of the protrusion 23 has an outwardly inclined slope structure, which allows for a smooth transition when the frustum 41 of the push rod 4 is advanced and the protrusion 23 is advanced.

[0051] like Figure 10-12 As shown, in specific usage:

[0052] Firstly, when the pre-filled syringe 1 is filled into the inner cavity of the inner shell 3, its outer diameter is slightly larger than the diameter of the inner cavity of the inner shell 3. It can be pressed into the inner shell 3 by external force. During the pressing process, the inner shell 3 will deform to a certain extent. After pressing, the inner shell 3 will recover its deformation, so that the pre-filled syringe 1 cannot be detached from the inner shell, thus improving its assembly firmness.

[0053] Subsequently, the inner housing 3 containing the pre-loaded syringe 1 is inserted from the rear end of the outer housing 2 to the designated position (at this time, the spring 5 is located at the bottom of the inner cavity of the outer housing 2, so that the inner housing 3 is in a state of compression against the spring 5). At this time, the grab 22 and the stop protrusion 24 on the outer housing 2 pass through the channel formed by the annular positioning member 31 and the locking member 32 on the inner housing 3, and realize that the protrusion 23 on the grab 22 locks the locking member 32 on the inner housing 3 (due to the reverse force of the spring 5 at the bottom of the inner housing 3). This achieves mutual pressing between the protrusion 23 and the locking member 32, so that the inner housing 3 cannot move in the front and back directions and is locked in the original position (this is the state when the safety device is not triggered).

[0054] During injection, the thumb pushes the plunger 4 to inject the pre-filled syringe 1. After the plunger 4 moves to the end, the first-stage frustum 41 at the rear end of the plunger 4 pushes the protrusion 23 on the gripper 22 to both sides until the protrusion 23 disengages from the locking member 32. During this deformation process, the upper inclined surfaces of the two protrusions 23 are impacted and squeezed by the frustum 41, and the whole gradually opens outward, which is equivalent to the sliding of a point on the inclined surface. The gripper 22 where the protrusion 23 is located can achieve a linear change process, so the change in the magnitude of the deformation force can be approximated as a linear change (the deformation of the gripper is elastic deformation). Therefore, the force of the operator's thumb pushing the plunger 4 is not abrupt, but a smooth change. And because the gripper 22 is slender, the deformation force at the end is smaller than that of a short and thick gripper. Therefore, when the thumb pushes the plunger 4 to fully open the protrusion 23 of the gripper 22 (the safety anti-needle puncture function is activated), the operator who is used to ordinary syringes will not have a significant difference in feeling.

[0055] When the safety anti-needle puncture function is activated, the inner shell 3 is pushed backward under the elastic force of the spring 5. The pre-loaded syringe 1 is pushed backward along with the inner shell 3 until the limiting block 301 on the inner shell 3 touches the upper edge of the strip-shaped slot 201 on the outer shell 2 and stops. After reaching this backward stop, the stop buckle 202 on the outer shell abuts against the annular rib 302 on the inner shell 3, so that the inner shell 3 cannot move up or down. The pre-loaded syringe 1 and the needle inside the inner shell 3 are locked in the current position, ensuring that the needle is locked after retracting into the outer shell and maintains a certain safe distance from the bottom opening of the outer shell 2 to prevent personnel from touching the needle.

[0056] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A passive anti-needle-puncture device for a syringe, comprising a pre-loaded syringe (1), an outer shell (2), an inner shell (3), a push rod (4), and a spring (5), characterized in that, The pre-filled syringe (1) is filled with a drug and is fixed in the middle cavity of the inner shell (3), with the front end extending outward. A push rod (4) is provided at the rear end of the inner shell (3) to push the drug in the pre-filled syringe (1). The rear end of the outer shell (2) is provided with a flange platform (21) that extends to both sides and is symmetrical. At the same time, a grab (22) along the axis of the outer shell (2) is provided on the flange platform (21). The top of the grab (22) is provided with an inwardly protruding protrusion (23). An annular positioning member (31) is provided at the rear end of the inner housing (3), and the annular positioning member (31) and the locking member (32) on the outer wall of the inner housing (3) form a channel for the passage of the grab (22), and is located at the bottom spring member (5) of the inner housing (3); When the push rod (4) is pushed forward for injection, the protrusion (23) of the grab (22) on the outer shell (2) forms a grab lock on the locking member (32) on the inner shell (3). After the pre-loaded syringe (1) is injected, the rear end of the push rod (4) forms an outward squeeze on the locking member (32), so that the locking member (32) on the inner shell (3) is released from the restraint of the grab (22). Under the action of the bottom spring (5), the pre-loaded syringe (1) is driven to rebound backward until the front tip of the pre-loaded syringe (1) is completely rebounded into the body of the outer shell (2). The bottom of the fastening surface where the protrusion (23) is located is set as an inward inclined slope structure, and the outer edge of the locking member (32) located on the inner shell (3) is set as an upward inclined slope, forming a locking engagement with the fastening surface of the protrusion (23); Both the outer shell (2) and the inner shell (3) are constructed as a single piece.

2. The passive anti-needle-puncture device for a syringe according to claim 1, characterized in that, A strip-shaped slot (201) extending along the axial direction is provided through the outer wall of the outer shell (2), and a limiting block (301) protruding outward is provided at the bottom of the inner shell (3), so that the movement area of ​​the limiting block (301) is embedded in the area formed by the strip-shaped slot (201) to limit the upward and downward position of the inner shell (3).

3. The passive anti-needle-puncture device for a syringe according to claim 2, characterized in that, The strip-shaped slot (201) is set at a symmetrical position on both sides of the outer shell (2), and two sets of limiting blocks (301) of the inner shell (3) are set simultaneously; the strip-shaped slot (201) and the flange platform (21) are perpendicularly distributed in the direction of extension.

4. The passive anti-needle-puncture device for a syringe according to claim 1, characterized in that, An annular rib (302) is provided on the outer wall of the inner shell (3) to cooperate with the inner wall of the outer shell (2) so as to ensure that the advancing direction of the inner shell (3) is the same as the extension direction of the inner cavity of the outer shell (2).

5. The passive anti-needle-puncture device for a syringe according to claim 4, characterized in that, A stop buckle (202) is provided on the outer wall of the outer shell (2), so that the front end of the stop buckle (202) protrudes into the inner side of the outer shell (2). When the inner shell (3) is pushed forward along the circumferential direction of the inner cavity of the outer shell (2), the stop buckle (202) limits the position of the annular rib (302) located on the upper part of the outer wall of the inner shell (3).

6. The passive anti-needle-puncture device for a syringe according to claim 1, characterized in that, The inward tilt angle of the protrusion (23) is between 1 and 20°.

7. The passive anti-needle-puncture device for a syringe according to claim 1, characterized in that, The rear end of the push rod (4) is configured as a frustum (41), and the frustum (41) is configured with two discs arranged vertically, with an annular groove (401) between the two discs.

8. The passive anti-needle-puncture device for a syringe according to claim 1, characterized in that, The upper end of the protrusion (23) has an outwardly inclined slope structure, which allows the truncated cone (41) of the push rod (4) to advance smoothly with the protrusion (23).

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