A dual chamber multi-stage syringe

Abstract

The utility model relates to the field of syringe, concretely relates to a double -cavity multistage syringe, include: outer syringe, inner syringe, valve subassembly and limiting component, outer syringe includes first piston, valve subassembly fluidly connected between the second output connector of inner syringe and the proximal end of first piston, is configured to allow fluid from the one -way flow of inner syringe to first fluid passage, inner syringe includes second piston and piston rod, limiting component includes at least two separable wedge, and the wedge is detachably installed between piston rod and second needle cylinder, the utility model discloses by inserting two separable wedges between piston rod and second needle cylinder, on one hand can prevent second piston from axial sliding in advance relative to second needle cylinder, on the other hand makes the axial thrust exerted by operator even, symmetrically passes to the circumferential edge of second needle cylinder proximal end through wedge, thereby improved the coaxial stability of first needle cylinder and second needle cylinder when pushing.

Description

Technical Field

[0001] This utility model relates to the field of syringes, specifically to a dual-chamber multi-stage syringe. Background Technology

[0002] Existing multistage syringes generally utilize the pressure difference between the two chambers with different opening pressures to achieve the sequential opening of the two chambers.

[0003] However, this design has a low tolerance for error. In real medical rescue or high-pressure operating environments, operators often find it difficult to accurately control the injection force and direction. When the operator applies too much force or the direction of force deviates from the central axis of the multi-stage syringe, the internal pressure distribution system will go out of control, which can easily cause the two chambers to open at the same time, resulting in unintended mixing of fluids. Utility Model Content

[0004] The purpose of this invention is to provide a dual-chamber multi-stage syringe to solve the problem of low fault tolerance in the technical means of achieving sequential opening of the two chambers by using the pressure difference of different opening pressures of the two chambers.

[0005] To solve the above-mentioned technical problems, this utility model specifically provides the following technical solution:

[0006] A dual-chamber multistage syringe, comprising:

[0007] An external syringe includes a first syringe and a first piston slidably disposed within the first syringe, the first syringe and the first piston together defining a first reservoir for containing a first fluid, the first piston having an axially penetrating first fluid channel, and the first syringe including a first output connector located at its distal end.

[0008] An internal syringe, at least partially slidably disposed within a first syringe, the internal syringe including a second syringe and a second piston slidably disposed within the second syringe, the second syringe and the second piston together defining a second reservoir for containing a second fluid, the proximal end of the second piston being connected to a piston rod having a radially outwardly extending flange, and the second syringe including a second output connector located at its distal end;

[0009] A valve assembly, fluidly connected between the second output connector and the proximal end of the first piston, is configured to allow fluid to flow unidirectionally from the internal syringe to the first fluid channel;

[0010] The limiting assembly includes at least two separable wedges, which are detachably mounted between the piston rod and the second syringe.

[0011] in:

[0012] In the first operating state, the wedge is inserted between the piston rod and the second syringe, with one end of the wedge abutting against the flange and the other end abutting against the second syringe, thereby transmitting the axial thrust applied to the piston rod to the second syringe, causing the second syringe to move synchronously to the distal end with the piston rod;

[0013] In the second operating state, the wedge is radially removed from the piston rod, thereby transferring the axial thrust applied to the piston rod to the second piston, causing the piston rod to move the second piston distally relative to the second syringe.

[0014] Furthermore, the wedge-shaped member has a tapered structure that is wide at one end and narrow at the other.

[0015] When in the first operating state, the wide end of the wedge abuts against the flange, and the narrow end of the wedge is at least partially inserted into the annular gap formed between the inner wall of the second syringe and the outer wall of the piston rod.

[0016] Furthermore, the wedge-shaped member includes a first wedge-shaped member and a second wedge-shaped member arranged symmetrically from left to right;

[0017] When the first wedge and the second wedge are clamped and assembled on the outside of the piston rod from opposite sides, the limiting assembly takes the shape of a frustum.

[0018] Furthermore, the side surface of the flange facing away from the wedge is constructed as a conical surface to form a reinforcing rib structure on the piston rod for bearing axial thrust.

[0019] Furthermore, the proximal outer periphery of the first syringe is provided with two radially outwardly extending first finger-shaped flanges, which are arranged in a straight line.

[0020] The second syringe has four radially outwardly extending second finger-shaped flanges on its proximal outer periphery, and the four second finger-shaped flanges are distributed in a cross shape.

[0021] The four second finger-shaped flanges, arranged in a cross shape, are configured to at least partially not geometrically overlap with the first finger-shaped flanges in the circumferential direction.

[0022] Furthermore, the valve assembly includes a valve body, a valve core, and a spring;

[0023] The valve housing has a second fluid channel inside, and the valve housing has an inlet end and an outlet end that communicate with the second fluid channel.

[0024] The valve core and the spring are disposed in the second fluid channel, the inlet end of the valve housing is sealed to the second output connector, and the outlet end of the valve housing is connected to the first fluid channel;

[0025] The spring force drives the valve core to move towards the proximal end of the valve housing, thereby blocking the liquid inlet end of the valve housing when no external force is applied.

[0026] Furthermore, the first piston is provided with a valve connector, which is detachably connected to the liquid outlet end of the valve housing, and the valve connector is provided with a limiting structure to restrict its rotation relative to the valve housing. The valve connector connects the liquid outlet end of the valve housing and the first fluid channel.

[0027] Furthermore, the inlet end of the valve housing is connected to the second output connector via a thread.

[0028] Furthermore, both the first output connector and the second output connector are standard Luer connectors.

[0029] Compared with the prior art, this application has the following advantages:

[0030] This invention improves the coaxial stability of the first and second syringes during injection by inserting two separable wedges between the piston rod and the second syringe. This prevents the second piston from sliding axially relative to the second syringe in advance and allows the axial thrust applied by the operator to be evenly and symmetrically transmitted to the circumferential edge of the proximal end of the second syringe through the wedges. Attached Figure Description

[0031] To more clearly illustrate the embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0032] Figure 1 This is a front view of the external syringe before injection in the first operating state of this embodiment of the invention;

[0033] Figure 2 for Figure 1 A cross-sectional view along the AA direction;

[0034] Figure 3 This is a perspective view of the first operating state of the present utility model embodiment, after the external syringe is injected;

[0035] Figure 4This is a perspective view of the second operating state of this utility model embodiment, before the injection of the internal syringe;

[0036] Figure 5 This is a perspective view of the second operating state of the present utility model embodiment, after the injection of the internal syringe.

[0037] Figure 6 This is an assembly diagram of the external syringe and the internal syringe according to an embodiment of the present utility model;

[0038] The labels in the diagram represent the following:

[0039] 1-External syringe; 11-First syringe; 111-First output connector; 112-First finger flange; 12-First piston; 121-First fluid channel; 13-First reservoir;

[0040] 2-Inner syringe; 21-Second syringe; 211-Second output connector; 212-Second finger flange; 22-Second piston; 221-Piston rod; 222-Flange; 23-Second reservoir;

[0041] 3-Valve assembly; 31-Valve housing; 311-Second fluid passage; 32-Valve core; 33-Spring;

[0042] 4-Limiting component; 41-Wedge-shaped part; 411-First wedge-shaped part; 412-Second wedge-shaped part. Detailed Implementation

[0043] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0044] refer to Figure 1 and Figure 2 This embodiment proposes a dual-chamber multi-stage syringe, including: an outer syringe 1, an inner syringe 2, a valve assembly 3, and a limiting assembly 4.

[0045] The external syringe 1 includes a first syringe 11 and a first piston 12 slidably disposed within the first syringe 11. The first syringe 11 and the first piston 12 together define a first reservoir 13 for containing a first fluid. A first fluid channel 121 is axially disposed within the first piston 12. The first syringe 11 includes a first output connector 111 located at its distal end.

[0046] The inner syringe 2 is at least partially slidably disposed within the first syringe 11. The inner syringe 2 includes a second syringe 21 and a second piston 22 slidably disposed within the second syringe 21. The second syringe 21 and the second piston 22 together define a second reservoir 23 for containing a second fluid. The proximal end of the second piston 22 is connected to a piston rod 221, and the piston rod 221 is provided with a radially outwardly extending flange 222. The second syringe 21 includes a second output connector 211 located at its distal end.

[0047] The valve assembly 3 connects the second output connector 211 to the proximal end of the first piston 12 and is configured to allow fluid to flow unidirectionally from the inner syringe 2 to the first fluid channel 121.

[0048] The limiting assembly 4 includes at least two separable wedges 41, which are detachably mounted between the piston rod 221 and the second syringe 21.

[0049] The multi-stage syringe has two operating states:

[0050] In the first operating state, the wedge 41 is inserted between the piston rod 221 and the second syringe 21, with one end of the wedge 41 abutting against the flange 222 and the other end abutting against the second syringe 21; when the piston rod 221 is pushed to the distal end, the second syringe 21 moves to the distal end synchronously with the piston rod 221.

[0051] In the second operating state, the wedge 41 is radially removed from the piston rod 221; when the piston rod 221 is pushed distally, the piston rod 221 drives the second piston 22 to move distally relative to the second syringe 21.

[0052] In this embodiment, two separable wedges 41 are inserted between the piston rod 221 and the second syringe 21, so that the axial thrust applied by the operator is uniformly and symmetrically transmitted to the circumferential edge of the proximal end of the second syringe 21 through the wedges 41, thereby improving the coaxial stability of the first syringe 11 and the second syringe 21 during injection.

[0053] Furthermore, if the limiting component 4 is merely a flat pad, it is prone to uneven force and radial slippage when subjected to high-pressure injection, and it is difficult to quickly and accurately align with the inner syringe 2 during assembly.

[0054] To address this issue, in this embodiment, the wedge 41 is a tapered structure that is wide at one end and narrow at the other. When in the first operating state, the wide end of the wedge 41 abuts against the flange 222, and the narrow end of the wedge 41 is at least partially inserted into the annular gap formed between the inner wall of the second syringe 21 and the outer wall of the piston rod 221.

[0055] Furthermore, the unilateral limiting or asymmetrical shape can cause the piston rod 221 to be subjected to eccentric force during injection, which can easily lead to bending of the piston rod 221 or failure of the piston seal. Moreover, the single-piece closed-loop structure cannot be radially removed without disassembling the piston rod 221.

[0056] refer to Figure 3 and Figure 4 To solve this problem, in this embodiment, the wedge 41 includes a first wedge 411 and a second wedge 412 arranged symmetrically from left to right; when the first wedge 411 and the second wedge 412 are clamped and assembled on the outside of the piston rod 221 from opposite sides, the limiting assembly 4 is in the shape of a frustum.

[0057] Furthermore, during operation, it is difficult for the user to accurately determine whether the fluid in the first reservoir 13 has been emptied by visual means alone. If the fluid is not completely emptied and the wedge 41 is removed blindly, it may lead to unintended mixing of the first fluid and the second fluid or inaccurate drug dosage.

[0058] To address this issue, in this embodiment, when the device transitions from the first operating state to the second operating state, the distal surface of the first piston 12 abuts against the distal inner wall of the first syringe 11, preventing the inner syringe 2 from moving further distally.

[0059] Furthermore, since non-standard interfaces cannot be directly and securely connected to standard medical devices such as intravenous catheters, catheters, or three-way valves widely used in clinical practice, the equipment has poor versatility and is prone to liquid leakage. To solve this problem, in this embodiment, both the first output connector 111 and the second output connector 211 are standard Luer connectors.

[0060] Furthermore, since the multi-stage syringe requires the operator to apply a great axial thrust when overcoming the friction of the dual pistons and the resistance of the internal valve, the conventional flat flange 222 is prone to buckling deformation or even fracture failure when compressed. In order to solve this problem, in this embodiment, the surface of the flange 222 facing away from the wedge 41 is constructed as a conical surface to form a reinforcing rib structure on the piston rod 221 to withstand the axial thrust.

[0061] Furthermore, since the inner syringe 2 moves to its limit position when the first liquid reservoir 13 is emptied, if the second syringe 21 also adopts the traditional straight lever structure, it is very easy for it to adhere and overlap with the first finger-shaped flange 112, making it difficult for the operator to pinch the second syringe 21 to perform blind operations such as rotation or separation when wearing medical gloves.

[0062] To address this issue, in this embodiment, the proximal outer periphery of the first syringe 11 is provided with two radially outwardly extending first finger-shaped flanges 112, which are arranged in a straight line; the proximal outer periphery of the second syringe 21 is provided with four radially outwardly extending second finger-shaped flanges 212, which are arranged in a cross shape; when the inner syringe 2 moves to its distal end to its limit position, the four cross-shaped second finger-shaped flanges 212 are configured to at least partially not geometrically overlap with the first finger-shaped flanges 112 in the circumferential direction.

[0063] Furthermore, in this embodiment, the valve assembly 3 includes a valve housing 31, a valve core 32, and a spring 33; the valve housing 31 has a second fluid channel 311 inside, and the valve housing 31 has an inlet end and an outlet end communicating with the second fluid channel 311; the valve core 32 and the spring 33 are disposed in the second fluid channel 311, the inlet end of the valve housing 31 is sealed to the second output connector 211, and the outlet end of the valve housing 31 is connected to the first fluid channel 121; the elastic force of the spring 33 drives the valve core 32 to move towards the proximal end of the valve housing 31, so that the valve core 32 blocks the inlet end of the valve housing 31 when no external force is applied.

[0064] Furthermore, when the inner syringe 2 needs to be assembled with the first piston 12, or when the independent inner syringe 2 is disassembled by rotation, if there is no torque transmission mechanism between the two, the valve housing 31 is prone to ineffective free rotation in the first piston 12, resulting in the inner syringe 2 not being able to be securely tightened or smoothly unscrewed.

[0065] To address this issue, in this embodiment, a valve connector is provided on the first piston 12. The valve connector is detachably connected to the liquid outlet end of the valve housing 31, and a limiting structure is provided on the valve connector to restrict its rotation relative to the valve housing 31. The valve connector connects the liquid outlet end of the valve housing 31 and the first fluid channel 121. The liquid inlet end of the valve housing 31 is connected to the second output connector 211 via a thread.

[0066] The working steps of this embodiment are as follows:

[0067] Step 1, refer to Figure 1 Initial preparation: After the device is pre-filled or the fluid is aspirated, the first liquid storage chamber 13 and the second liquid storage chamber 23 respectively store the first fluid and the second fluid to be delivered; at this time, two symmetrical wedge-shaped pieces 41 are tightly fitted between the conical flange 222 of the piston rod 221 and the proximal end of the second syringe 21, thereby constructing a rigid force transmission interference between the piston rod 221 and the second syringe 21, making the entire internal syringe 2 form a rigid whole; the valve assembly 3 remains normally closed under the elastic force of the spring 33 to ensure strict isolation of the fluids in the two chambers.

[0068] Step 2, refer to Figure 2and Figure 3 The operator presses the piston rod 221 from the proximal end to the distal end to apply a thrust. Due to the conical reinforcing rib design on the back side of the flange 222, the thrust is stably borne and transmitted evenly and symmetrically to the circumferential edge of the second syringe 21 via the wedge 41. The inner syringe 2 pushes the first piston 12 to move distally within the first syringe 11, thereby smoothly discharging the first fluid in the first reservoir 13 through the first output connector 111. During this process, the valve assembly 3 is simultaneously subjected to the closing thrust of the spring 33 and the back pressure of the fluid in the first reservoir 13. The valve core 32 firmly seals the inlet end to prevent the fluid from flowing back or mixing prematurely.

[0069] Step 3, refer to Figure 3 and Figure 4 Bottom out and pause: When the first fluid is emptied, the distal surface of the first piston 12 physically abuts against the distal inner wall of the first syringe 11; at this time, the inner syringe 2 can no longer move distally.

[0070] Step 4, refer to Figure 4 Unlocking: After confirming the completion of the first stage, the operator pulls out and removes the two wedge-shaped pieces 41 radially from the side of the device. The rigid force transmission interference between the flange 222 of the piston rod 221 and the second syringe 21 is released, and the device transitions from the first operating state to the second operating state.

[0071] Step 5, refer to Figure 5 Injecting syringe 2: The operator pushes the piston rod 221 distally again. The piston rod 221 drives the second piston 22 to slide distally inside the second syringe 21. The hydraulic pressure in the second reservoir 23 rises rapidly, thereby overcoming the elastic force of the spring 33 of the valve assembly 3 to push open the valve core 32. The valve assembly 3 is opened, and the second fluid flows through the valve shell 31 and the first fluid channel 121 inside the first piston 12, and is finally discharged through the first output connector 111, completing the second stage of fluid delivery.

[0072] Step Six, refer to Figure 6 Separation: After the second liquid storage chamber 23 is emptied, the inner syringe 2 is subjected to torque by utilizing the cross-shaped distribution of the second finger-shaped flange 212, thereby detaching the threaded connection between the liquid inlet end of the valve housing 31 and the second output connector 211, and completing the disassembly and separation of the inner syringe 2.

[0073] The above embodiments are merely exemplary embodiments of this utility model and are not intended to limit this utility model. The scope of protection of this utility model is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to this utility model within its substance and scope of protection, and such modifications or equivalent substitutions should also be considered as falling within the scope of protection of this utility model.

Claims

1. A dual-chamber multi-stage syringe, characterized in that, include: An external syringe (1) includes a first syringe (11) and a first piston (12) slidably disposed within the first syringe (11). The first syringe (11) and the first piston (12) together define a first reservoir (13) for containing a first fluid. A first fluid channel (121) is axially disposed within the first piston (12). The first syringe (11) includes a first output connector (111) located at its distal end. An internal syringe (2) is at least partially slidably disposed within a first syringe (11). The internal syringe (2) includes a second syringe (21) and a second piston (22) slidably disposed within the second syringe (21). The second syringe (21) and the second piston (22) together define a second reservoir (23) for containing a second fluid. A piston rod (221) is connected to the proximal end of the second piston (22). A radially outwardly extending flange (222) is provided on the piston rod (221). The second syringe (21) includes a second output connector (211) located at its distal end. The valve assembly (3), fluidly connected between the second output connector (211) and the proximal end of the first piston (12), is configured to allow fluid to flow unidirectionally from the internal syringe (2) to the first fluid channel (121). The limiting assembly (4) includes at least two separable wedges (41) that are detachably mounted between the piston rod (221) and the second syringe (21); in, In the first operating state, the wedge (41) is inserted between the piston rod (221) and the second syringe (21), with one end of the wedge (41) abutting against the flange (222) and the other end abutting against the second syringe (21), thereby transmitting the axial thrust applied to the piston rod (221) to the second syringe (21), so that the second syringe (21) moves synchronously to the distal end with the piston rod (221); In the second operating state, the wedge (41) is radially removed from the piston rod (221), thereby transmitting the axial thrust applied to the piston rod (221) to the second piston (22), causing the piston rod (221) to drive the second piston (22) to move distally relative to the second syringe (21).

2. The dual-chamber multi-stage syringe according to claim 1, characterized in that: The wedge (41) is a tapered structure that is wide at one end and narrow at the other. When in the first operating state, the wide end of the wedge (41) abuts against the flange (222), and the narrow end of the wedge (41) is at least partially inserted into the annular gap formed between the inner wall of the second syringe (21) and the outer wall of the piston rod (221).

3. The dual-chamber multi-stage syringe according to claim 2, characterized in that: The wedge (41) includes a first wedge (411) and a second wedge (412) arranged symmetrically from left to right. When the first wedge (411) and the second wedge (412) are respectively clamped and assembled from opposite sides outside the piston rod (221), the limiting assembly (4) is generally in the shape of a frustum.

4. The dual-chamber multi-stage syringe according to claim 1, characterized in that: The side surface of the flange (222) facing away from the wedge (41) is constructed as a conical surface to form a reinforcing rib structure on the piston rod (221) for bearing axial thrust.

5. The dual-chamber multi-stage syringe according to claim 1, characterized in that: The first syringe (11) has two radially outwardly extending first finger-shaped flanges (112) on its proximal outer periphery, and the two first finger-shaped flanges (112) are arranged in a straight line. The second syringe (21) has four radially outwardly extending second finger-shaped flanges (212) on its proximal outer periphery, and the four second finger-shaped flanges (212) are arranged in a cross shape; The four second finger flanges (212) arranged in a cross shape are configured to at least partially not geometrically overlap with the first finger flange (112) in the circumferential direction.

6. The dual-chamber multi-stage syringe according to claim 1, characterized in that: The valve assembly (3) includes a valve housing (31), a valve core (32), and a spring (33). The valve housing (31) is provided with a second fluid channel (311) inside, and the valve housing (31) is provided with an inlet end and an outlet end that communicate with the second fluid channel (311); The valve core (32) and the spring (33) are disposed in the second fluid channel (311), the inlet end of the valve housing (31) is sealed to the second output connector (211), and the outlet end of the valve housing (31) is connected to the first fluid channel (121). The elastic force of the spring (33) drives the valve core (32) to move toward the proximal end of the valve housing (31), so that the valve core (32) blocks the liquid inlet end of the valve housing (31) when no external force is applied.

7. The dual-chamber multi-stage syringe according to claim 6, characterized in that: The first piston (12) is provided with a valve connector, which is detachably connected to the liquid outlet end of the valve housing (31), and the valve connector is provided with a limiting structure that restricts its rotation relative to the valve housing (31). The valve connector connects the liquid outlet end of the valve housing (31) and the first fluid channel (121).

8. The dual-chamber multi-stage syringe according to claim 7, characterized in that: The inlet end of the valve body (31) is connected to the second output connector (211) by a thread.

9. The dual-chamber multi-stage syringe according to claim 1, characterized in that: Both the first output connector (111) and the second output connector (211) are standard Luer connectors.

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