Pre-filled catheter flusher

Abstract

The utility model provides a pre-filling type catheter flusher which comprises a liquid storage container 1 storing flushing liquid, an injection head 3 connected to the liquid storage container 1 and a pressure valve 2 connected to the injection head 3, the injection head 3 is communicated with an inner cavity of the liquid storage container 1, and a resistance increasing mechanism 4 is arranged between the pressure valve 2 and the injection head 3. The resistance increasing mechanism 4 increases the resistance of opening the pressure valve 2 towards one end of the liquid storage container 1, when injection of the flushing fluid is stopped, the flushing fluid can be prevented from flowing back, and when injection and pumpback are conducted, whether blood returns to the needle tube or not can be recognized.

Description

Technical Field

[0001] The utility model relates to the technical field of medical devices, in particular to a prefilled catheter flusher used for catheter flushing. Background Art

[0002] Intravenous catheters are widely used in clinical practice because they reduce the pain and needle phobia associated with repeated venipunctures, alleviate patient anxiety, facilitate medication administration, reduce nurse workload, and alleviate patient pain. During the lifespan of an intravenous catheter, the incidence of catheter occlusion is high, primarily due to thrombosis. Severe occlusion can render the catheter inoperable and necessitate premature removal, increasing the workload of healthcare professionals and causing additional pain and financial burden for patients. To avoid these issues, catheter flushing is necessary before and after each infusion, after administering high-viscosity flushing solutions, between flushing solutions with incompatible properties, and during regular maintenance between infusions. The most commonly used catheter flushing method is a standard syringe. Nurses use a disposable sterile syringe to aspirate saline from a bulk or individually packaged container to prepare the sealing solution. However, the need for pre-preparation complicates the procedure and carries a higher risk of infection. Another alternative is the use of a prefilled catheter flusher. Existing prefilled catheter flushers use a structure similar to that of traditional syringes. The rubber piston needs to be coated with silicone oil, which will result in a high content of insoluble particles in the flushing liquid. In addition, since the piston rod can move back and forth, the open area may cause contamination during the backward pulling process. The patent (publication number CN 203802807 U) discloses an anti-reflux plastic ampoule that can be used for indwelling needle sealing / flushing tubes. The ampoule includes an ampoule body and a nipple connected to the top of the ampoule body. The nipple is connected to the inside of the ampoule body, and a one-way valve for one-way conduction of the nipple is provided at the connection between the nipple and the ampoule body. When sealing / flushing the indwelling needle, the device can ensure that the flushing liquid can only flow out in one direction and will not flow back, thereby preventing blood from flowing back. Compared to existing prefilled catheter flushers, this device does not require piston siliconization. However, when the device stops sealing / flushing the indwelling needle, the ampoule body rebounds, creating negative pressure inside the ampoule body. This negative pressure still causes the one-way valve to slightly deform toward one end of the ampoule body, causing flushing fluid to flow back, making it impossible to prevent blood backflow and catheter blockage. Furthermore, when aspiration is needed to confirm whether the indwelling needle is clogged, the one-way valve in this device only allows flushing fluid to flow outward from the ampoule body, making it impossible to verify blood flow back into the needle through aspiration.

[0003] Therefore, technical personnel in this field urgently need to develop a prefilled catheter flusher with a simple structure and easy operation, which can prevent the backflow of flushing fluid when sealing / flushing the indwelling needle, and can resist the backflow of flushing fluid caused by the slight deformation of the pressure valve when stopping sealing / flushing the indwelling needle, and can identify whether blood is returning to the needle tube by backdrawing. Summary of the Invention

[0004] The utility model provides a prefilled catheter flusher with a simple structure and convenient operation. It can prevent the backflow of flushing liquid when sealing / flushing the indwelling needle, and can resist the backflow of flushing liquid caused by the slight deformation of the pressure valve when stopping sealing / flushing the indwelling needle, and can identify whether blood has returned to the needle tube by back drawing.

[0005] The utility model provides a prefilled catheter flusher, which comprises: a liquid storage container capable of storing flushing liquid, an injection head connected to the liquid storage container, and a pressure valve connected to the injection head, wherein the injection head is communicated with the interior of the liquid storage container; a resistance increasing mechanism is provided between the pressure valve and the injection head, wherein the resistance increasing mechanism can increase the resistance of the pressure valve when it opens toward one end of the liquid storage container.

[0006] The pressure valve is a component that applies pressure. It allows the flushing liquid to flow from the injection head to the outside world while also applying pressure to effectively prevent the flushing liquid from flowing back into the container cavity. In the embodiments of this application, the pressure valve is diaphragmatic and has a slit. However, those skilled in the art will appreciate that pressure valves of other shapes can also achieve the function of applying pressure.

[0007] In an embodiment of the present application, the resistance increasing mechanism is a component that can limit the deformation space of the pressure valve toward one end of the liquid storage container. In another embodiment, the resistance increasing mechanism is a component that can apply a force to the pressure valve to resist the deformation of the pressure valve.

[0008] In the embodiment of the present application, the resistance-increasing mechanism is a hollow elastic sheet; in another embodiment, the resistance-increasing mechanism is one or more elastic strips, preferably multiple elastic strips; in another embodiment, the resistance-increasing mechanism is a resistance-increasing component with a variable cross-sectional area. However, those skilled in the art will appreciate that components of other shapes that can achieve the resistance-increasing function may also be used in the present invention.

[0009] Preferably, the resistance increasing mechanism is a component with a variable cross-sectional area. Further preferably, the component with a variable cross-sectional area is an annular component, a semi-annular component or other component with an irregular cross-section.

[0010] The component with a changing cross-sectional area may be an independent component fixedly connected to the inner periphery of the injection head; or, the component with a changing cross-sectional area may be a component integrally formed with the injection head.

[0011] When using the prefilled catheter flusher provided by this utility model to seal / flush an indwelling needle, the flusher's resistance-increasing mechanism increases the resistance to the pressure valve opening toward one end of the fluid reservoir, effectively preventing backflow of flushing fluid and, consequently, blood reflux that could lead to catheter blockage. When backdraw is required to confirm whether the indwelling needle is clogged, the fluid reservoir is stretched to create a negative pressure within the cavity. Blood reflux can then be identified by determining whether the flushing fluid refluxes under the negative pressure.

[0012] The pre-filled catheter flusher further comprises a locking joint, the locking joint is hollow and tubular, the locking joint is an independent component and is connected to the end of the injection head away from the liquid storage container, and the pressure valve is compressed between the locking joint and the injection head.

[0013] The locking joint not only facilitates the connection of the pre-filled catheter flusher and the infusion joint, but also facilitates the compression and sealing of the pressure valve in the injection head, ensures that the flushing liquid flows out of the cracks in the pressure valve, and avoids the leakage of the flushing liquid along the connection between the pressure valve, the injection head and the locking joint.

[0014] The outer side wall of the locking joint is provided with an extrusion auxiliary part extending outward, which can assist the hand to extrude the liquid storage container to be compressed and deformed.

[0015] The pre-filled catheter flusher further comprises a sealing component, which is used to block the locking joint to prevent the flushing liquid in the container cavity from flowing out to the outside, and the sealing component can be a sealing cap and is in sealing connection with the locking joint; the sealing component is part of the locking joint, and a flat head is formed by heat sealing the end of the locking joint away from the injection head; the sealing component is a heat sealing film and is heat sealed with the end of the locking joint away from the injection head.

[0016] The above-mentioned locking joint wall further has a shoulder portion, which facilitates the compression and sealing of the pressure valve in the end of the locking joint by the injection head.

[0017] Preferably, the inner wall of the shoulder portion is provided with a limiting table extending to one end of the pressure valve, and the pressure valve is compressed between the limiting table and the injection head.

[0018] Further preferably, the inner wall of the shoulder portion inside the limiting table is further provided with a limiting protrusion extending to one end of the pressure valve, and the pressure valve is compressed between the limiting table, the limiting protrusion and the injection head.

[0019] When the injection of the flushing liquid is stopped, the pressure valve is slightly deformed in the direction of the end of the liquid storage container under the action of negative pressure, in order to prevent the backflow of the flushing liquid caused by the slight deformation of the pressure valve, a buffer mechanism is arranged between the end of the locking joint away from the injection head and the pressure valve, the buffer mechanism is a component with elasticity, when the flushing liquid flows from the injection head to the locking joint, the buffer mechanism is compressed; when the flushing liquid stops flowing, the buffer mechanism partially or completely restores to the original state and pushes the flushing liquid to flow from the injection head to the locking joint, thereby resisting the slight deformation of the pressure valve in the direction of the end of the liquid storage container to cause the backflow of the flushing liquid.

[0020] In the embodiments of the present application, the buffer mechanism is a flexible part provided on the inner wall of the locking joint, such as a part of the inner wall made of elastic material. When the flushing liquid flows from the injection head to the locking joint, the flexible part is compressed. When the flushing liquid stops flowing, the flexible part partially or entirely returns to its original state and pushes the flushing liquid to flow from the injection head to the locking joint, thereby resisting the slight deformation of the pressure valve in the direction of the liquid storage container and preventing the backflow of the flushing liquid. In another embodiment, the buffer mechanism is an elastic membrane provided on the inner wall of the locking joint and a first buffer cavity provided on the inner wall of the locking joint to limit the deformation of the elastic membrane. When the flushing liquid flows from the injection head to the locking joint, the elastic membrane is compressed and the first buffer cavity buffers the compression deformation of the elastic membrane. When the flushing liquid stops flowing, the elastic membrane partially or entirely returns to its original state and pushes the flushing liquid to flow from the injection head to the locking joint, thereby resisting the slight deformation of the pressure valve in the direction of the liquid storage container and preventing the backflow of the flushing liquid. In another embodiment, the buffer mechanism is an elastic protrusion provided on the inner wall of the locking joint. When the flushing liquid flows from the injection head to the locking joint, the elastic protrusion is compressed. When the flushing liquid stops flowing, the elastic protrusion partially or entirely returns to its original state and pushes the flushing liquid to flow from the injection head to the locking joint, thereby resisting the slight deformation of the pressure valve in the direction of the liquid storage container and preventing the backflow of the flushing liquid. In another embodiment, the buffer mechanism is a non-enclosed air chamber provided on the inner wall of the locking joint. When the flushing liquid flows from the injection head to the locking joint, the air in the air chamber is compressed. When the flushing liquid stops flowing, the air in the air chamber partially or entirely diffuses and pushes the flushing liquid to flow from the injection head to the locking joint, thereby resisting the slight deformation of the pressure valve in the direction of the liquid storage container and preventing the backflow of the flushing liquid.

[0021] To fully utilize the flushing liquid in the liquid storage container and facilitate the test of backflow, the liquid storage container can adopt a cavity with variable volume, preferably a bellows that can stretch and contract in the longitudinal direction. In another embodiment, the liquid storage container is a squeezable liquid storage bag, at least part of the wall of which is a flexible part.

[0022] To facilitate the use of the operator, the diameter of the liquid storage container at the end far from the injection head is greater than the diameter of the end close to the injection head in the embodiments of the present application. In another embodiment, a pull ring is provided at the end of the liquid storage container far from the injection head to facilitate the force exerted by the hand.

[0023] In the embodiments of the present application, the liquid storage container is provided with a container port, and the injection head is fixedly connected to the container port and connected by means of threading, welding, or adhesion. In another embodiment, the injection head is a part extending from the peripheral wall of the container port.

[0024] Advantages

[0025] First, the pre-filled catheter flusher provided by the utility model has simple structure relative to traditional syringes, does not need to be siliconized, and effectively reduces soluble particles in the flushing liquid. In addition, the pre-filled catheter flusher is provided with a resistance increasing mechanism between the pressure valve and the injection head. The resistance increasing mechanism can limit the deformation space of the pressure valve in the direction of the liquid storage container or apply a force to resist the deformation of the pressure valve, increase the resistance of the pressure valve in the direction of the liquid storage container, effectively prevent the backflow of the flushing liquid, and avoid the blockage of the catheter caused by the backflow of blood. When it is necessary to confirm whether the indwelling needle is blocked by backflow, the device can overcome the resistance of the resistance increasing mechanism to realize the backflow of the flushing liquid, and then identify whether the needle tube is backflowed with blood.

[0026] Second, the injection head of the utility model can be integrally formed with the liquid storage container, has few parts, and has simple structure. Alternatively, the injection head can be separately formed with the liquid storage container, facilitating product processing and manufacturing.

[0027] Third, the locking joint of the utility model not only facilitates the connection of the pre-filled catheter flusher and the infusion joint, but also is beneficial to the compression sealing of the pressure valve in the injection head, ensures that the flushing liquid is completely injected to the outside through the crack, avoids the leakage of the flushing liquid along the connection between the pressure valve, the injection head and the locking joint, and the backflow of the flushing liquid into the inner cavity of the container along the connection between the pressure valve, the injection head and the locking joint. The wall of the locking joint can be provided with a shoulder portion, which facilitates the compression sealing of the pressure valve in one end of the locking joint by the injection head. The inner wall of the shoulder portion can be provided with a limiting table, which enhances the sealing between the pressure valve, the locking joint and the injection head through linear sealing. In order to further enhance the sealing between the pressure valve, the locking joint and the injection head, the inner wall of the shoulder portion on the inner side of the limiting table is provided with a limiting protrusion, realizing the double linear sealing of the limiting table and the limiting protrusion.

[0028] Fourth, the pre-filled catheter flusher provided by the utility model can resist the backflow of the flushing liquid caused by the slight deformation of the pressure valve in the direction of the liquid storage container, and avoid the risk of the blockage of the catheter caused by the backflow of blood. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 : the pre-filled catheter flusher of the utility model embodiment is fully cut and exploded;

[0030] Figure 2 : the pre-filled catheter flusher of the utility model embodiment is fully cut and exploded;

[0031] Figure 3 : the pre-filled catheter flusher of the utility model embodiment is fully cut and exploded;

[0032] Figure 4Embodiment of the utility model discloses pre -filled catheter flusher's liquid storage container's full section view;

[0033] Figure 5 Embodiment of the utility model discloses pre -filled catheter flusher's gas chamber's structural diagram;

[0034] Figure 6 Embodiment of the utility model discloses pre -filled catheter flusher's liquid storage container is the structural diagram of bag -like structure;

[0035] Figure 7 Embodiment of the utility model discloses pre -filled catheter flusher's cross -sectional area change's component is the structural diagram of ring shape;

[0036] Figure 8 Embodiment of the utility model discloses pre -filled catheter flusher's cross -sectional area change's component is the structural diagram of half ring shape;

[0037] Figure 9 Embodiment of the utility model discloses pre -filled catheter flusher's cross -sectional area change's component is the structural diagram of irregular shape;

[0038] Figure 10 Embodiment of the utility model discloses pre -filled catheter flusher's hollow elastic sheet's structural diagram;

[0039] Figure 11 Embodiment of the utility model discloses pre -filled catheter flusher's elastic strip's structural diagram.

[0040] 1. liquid storage container;10. container mouth;11. container inner chamber;12. container side wall;13. container bottom wall;2. pressure valve;21. crack;3. injection head;4. resistance increasing mechanism;41. hollow elastic sheet;42. elastic strip;43. cross-sectional area change component;5. buffer mechanism;51. elastic film;52. first buffer cavity;53. elastic protrusion;54. gas chamber;541. gas cavity mouth;6. locking joint;60. joint inner chamber;61. joint side wall;611. extrusion auxiliary component;62. liquid inlet;63. liquid outlet;64. collar;641. internal thread;65. shoulder;651. limiting platform;652. limiting protrusion;7. pull ring;8. sealing component. DETAILED DESCRIPTION

[0041] The exemplary embodiments will be described in detail herein below with reference to the drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the embodiments of the present disclosure. The following exemplary embodiments are described with reference to the drawings, wherein like reference numerals represent like elements which are the same or similar function or results. The embodiments described in the following exemplary embodiments do not represent all the implementations in accordance with this disclosure. Instead, they simply help understand the apparatus and methods in accordance with some aspects of the present disclosure as recited in the claims.

[0042] The present utility model provides a prefilled catheter flusher. The first embodiment of the prefilled catheter flusher provided by the present utility model is described below.

[0043] like Figure 1 A prefilled catheter flusher is shown. The device comprises a fluid reservoir 1, the inner cavity of which is prefilled with flushing fluid, an injection head 3 that allows the flushing fluid to be injected into the environment, and a pressure valve 2 that prevents the flushing fluid from flowing back into the inner cavity of the fluid reservoir 1. The fluid reservoir 1 is preferably a retractable bellows, blow-molded from medical plastic, and comprises a container opening 10, container sidewalls 12, and container bottom wall 13. The container sidewalls 12 and container bottom wall 13 together form an inner cavity 11 prefilled with flushing fluid. The injection head 3 is connected to the fluid reservoir 1 and is formed by extending outward from the peripheral wall of the container opening 10. The injection head 3 is integrally formed with the fluid reservoir 1, resulting in a minimal number of parts, a simple structure, and an airtight seal. This makes it easy to operate and assemble, simplifying the assembly process and facilitating mass production. To fully utilize the flushing fluid in the fluid reservoir 1 for sealing / flushing the indwelling needle, the fluid reservoir 1 is a longitudinally retractable bellows, with the container opening 10 located at the top of the fluid reservoir 1.

[0044] Continue to refer Figure 1 To facilitate connection of the device to the infusion connector, the injection head 3 is sealed and fixed with a locking connector 6. The locking connector 6 is made of injection-molded medical plastic material and includes a connector sidewall 61, a liquid inlet 62, and a liquid outlet 63. The connector sidewall 61 encloses a connector inner cavity 60. One end of the connector inner cavity 60 is provided with a liquid inlet 62 connected to the injection head 3, and the other end is provided with a liquid outlet 63 for injection of flushing liquid. The outer wall of the connector sidewall 61 has a collar 64 extending along the axial direction of the locking connector 6 to the end of the liquid outlet 63. The collar 64 is provided with an internal thread 641 that cooperates with the infusion connector. To facilitate the sealing and pressing of the pressure valve 2 against the injection head 3, the connector sidewall 61 has a shoulder 65. The pressure valve 2 is pressed and sealed between the shoulder 65 and the injection head 3. Furthermore, the inner wall of the shoulder 65 is provided with a stopper 651 extending to the end of the pressure valve 2. This stopper 651 enhances the sealing between the pressure valve 2, the locking connector 6, and the injection head 3 through a linear seal. Furthermore, the inner wall of the shoulder 65, located inside the stopper 651, is provided with a stopper protrusion 652 extending to the end of the pressure valve 2. This dual linear seal of the stopper 651 and the stopper protrusion 652 further enhances the sealing between the pressure valve 2, the locking connector 6, and the injection head 3. The sealed connection between the outer periphery of the pressure valve 2, the port of the injection head 3, and the locking connector 6 prevents flushing liquid from flowing back into the container cavity 11 along the connection between the outer periphery of the pressure valve 2, the port of the injection head 3, and the locking connector 6, and prevents flushing liquid from leaking out along the connection between the outer periphery of the pressure valve 2, the port of the injection head 3, and the locking connector 6.

[0045] With reference to the foregoing Figure 1 , the pressure valve 2 allows the flushing liquid to flow from the injection head 3 to the outside while effectively preventing the flushing liquid from flowing back to the container cavity 11. The pressure valve 2 is in the form of a diaphragm made of medical silicone. The pressure valve 2 is provided with a slit 21 in the form of a straight line, a cross or a T shape. The slit 21 is in a closed state under its own elasticity in a natural state and is opened when subjected to a certain pressure. The pressure valve 2 is provided with a resistance increasing mechanism 4 between the pressure valve 2 and the injection head 3. The resistance increasing mechanism 4 increases the resistance of the pressure valve 2 to open in the direction of the end of the liquid storage container 1. When injecting the flushing liquid, the liquid storage container 1 is compressed and deformed by hand. At this time, the pressure of the container cavity 11 is increased. The flushing liquid in the container cavity 11 pushes open the slit 21 of the pressure valve 2, so that the flushing liquid flows from the container cavity 11 to the outside through the injection head 3. When stopping the injection of the flushing liquid, the liquid storage container 1 rebounds to form a negative pressure in the cavity. In order to prevent the pressure valve 2 from deforming in the direction of the end of the liquid storage container 1 under the action of the negative pressure, the resistance increasing mechanism 4 increases the resistance of the pressure valve 2 to open in the direction of the end of the liquid storage container 1, so as to prevent the pressure valve 2 from deforming in the direction of the end of the liquid storage container 1, thereby preventing the flushing liquid from flowing back and avoiding the blood flowing back to cause the catheter to be blocked. When it is necessary to confirm whether the needle tube is blocked by backflow, the cavity of the liquid storage container 1 is stretched to generate a negative pressure under the action of the negative pressure. The pressure valve 2 overcomes the resistance applied by the resistance increasing mechanism 4 and opens in the direction of the end of the liquid storage container 1. Whether the needle tube is backflowed is identified by the backflow of the flushing liquid, thereby identifying whether the needle tube is blocked. As shown in Figure 4 In order to facilitate the stretching of the liquid storage container 1, the diameter of the end of the liquid storage container 1 away from the injection head 3 is greater than the diameter of the end of the liquid storage container 1 close to the injection head 3. This structure has the effect of assisting the hand force to stretch the liquid storage container 1. Alternatively, the end of the liquid storage container 1 away from the container port 10 is provided with a pull ring 7. The pull ring 7 has the effect of assisting the hand force to stretch the liquid storage container 1.

[0046] As shown in Figure 6 , alternatively, the liquid storage container 1 is a squeezable liquid storage bag. At least part of the wall of the liquid storage container 1 is an elastic part. When it is necessary to confirm whether the needle tube is blocked by backflow, the elastic part of the liquid storage container 1 is stretched outward to generate a negative pressure in the cavity under the action of the negative pressure. The pressure valve 2 overcomes the resistance applied by the resistance increasing mechanism 4 and opens in the direction of the end of the liquid storage container 1. Whether the needle tube is backflowed is identified by the backflow of the flushing liquid, thereby identifying whether the needle tube is blocked.

[0047] In this embodiment, the resistance increasing mechanism 4 can also select other mechanical structures as long as it can increase the resistance of the pressure valve 2 to open in the direction of the end of the liquid storage container 1.

[0048] With reference to the foregoing Figure 1, the resistance increasing mechanism 4 can apply a force against the deformation of the pressure valve 2 to increase the resistance of the pressure valve 2 to open in the direction of the one end of the liquid storage container 1. As shown in Figure 10 , specifically, the resistance increasing mechanism 4 is a hollow elastic sheet 41 arranged between the pressure valve 2 and the injection head 3, which is made of medical silica gel material, and the hollow elastic sheet 41 is attached to the pressure valve 2 at the one end of the liquid storage container 1. The hollow elastic sheet 41 applies a force against the deformation of the pressure valve 2, and the outer periphery of the hollow elastic sheet 41 is fixedly connected to the inner periphery of the port of the injection head 3. When injecting the flushing liquid, the flushing liquid flows through the hollow elastic sheet 41 to open the crack 21 of the pressure valve 2, so that the flushing liquid flows from the inner cavity 11 of the container to the outside through the injection head 3. When stopping the injection of the flushing liquid, the hollow elastic sheet 41 increases the resistance of the pressure valve 2 to open in the direction of the one end of the liquid storage container 1, and prevents the pressure valve 2 from deforming in the direction of the liquid storage container 1, thereby preventing the backflow of the flushing liquid and avoiding the blockage of the catheter caused by the backflow of blood. Further, the elasticity of the hollow elastic sheet 41 is greater than the elasticity of the pressure valve 2, which effectively increases the resistance of the pressure valve 2 to open in the direction of the one end of the liquid storage container 1; or the hardness of the hollow elastic sheet 41 is greater than the hardness of the pressure valve 2, which also effectively increases the resistance of the pressure valve 2 to open in the direction of the one end of the liquid storage container 1.

[0049] When stopping the injection of the flushing liquid, the liquid storage container 1 is reset to form a negative pressure in the inner cavity 11, and at this time the pressure valve 2 will still deform slightly in the direction of the one end of the liquid storage container 1 under the action of the negative pressure. In order to resist the backflow of the flushing liquid caused by the slight deformation of the pressure valve 2 in the direction of the one end of the liquid storage container 1, the device further comprises a buffer mechanism 5 arranged on the joint side wall 61 between the liquid outlet 63 of the locking joint 6 and the pressure valve 2. The buffer mechanism 5 is an elastic part arranged on the inner wall of the locking joint 6, which is made of an elastic material. When injecting the flushing liquid, the flushing liquid flows from the injection head 3 to the locking joint 6, and the elastic part is compressed by the flushing liquid; when stopping the injection of the flushing liquid, the liquid storage container 1 is reset to form a negative pressure in the inner cavity 11, and the elastic part is partially or completely restored to its original state by its own elasticity and under the action of the negative pressure in the inner cavity 11, and pushes the flushing liquid to flow from the injection head 3 to the locking joint 6, thereby preventing the backflow of the flushing liquid and further avoiding the blockage of the catheter caused by the backflow of blood.

[0050] Continuing to refer to Figure 1Optionally, the buffer mechanism 5 is provided with an elastic film 51 on the inner wall of the joint side wall 61, and a first buffer cavity 52 is formed by the deformation of the elastic film 51 on the inner wall of the joint side wall 61. The elastic film 51 is made of elastic material. When the flushing liquid is injected, the flushing liquid flows from the injection head 3 to the locking joint 6, the elastic film 51 is compressed by the flushing liquid, and at this time the first buffer cavity 52 buffers the compression deformation of the elastic film 51; when the injection of the flushing liquid is stopped, the liquid storage container 1 is reset to form a negative pressure in the container cavity 11, the elastic film 51 is partially or completely restored to its original state by its own elasticity and the negative pressure in the container cavity 11, and the flushing liquid is pushed to flow from the injection head 3 to the locking joint 6, thereby preventing the backflow of the flushing liquid, and further preventing the backflow of blood causing the catheter to be blocked.

[0051] Reference Figure 2 Optionally, the buffer mechanism 5 is provided with an elastic film 51 on the inner wall of the joint side wall 61, and a first buffer cavity 52 is formed by the deformation of the elastic film 51 on the inner wall of the joint side wall 61. The elastic film 51 is made of elastic material. When the flushing liquid is injected, the flushing liquid flows from the injection head 3 to the locking joint 6, the elastic film 51 is compressed by the flushing liquid, and at this time the first buffer cavity 52 buffers the compression deformation of the elastic film 51; when the injection of the flushing liquid is stopped, the liquid storage container 1 is reset to form a negative pressure in the container cavity 11, the elastic film 51 is partially or completely restored to its original state by its own elasticity and the negative pressure in the container cavity 11, and the flushing liquid is pushed to flow from the injection head 3 to the locking joint 6, thereby preventing the backflow of the flushing liquid, and further preventing the backflow of blood causing the catheter to be blocked.

[0052] Reference Figure 5 Optionally, the buffer mechanism 5 is provided with an elastic film 51 on the inner wall of the joint side wall 61, and a first buffer cavity 52 is formed by the deformation of the elastic film 51 on the inner wall of the joint side wall 61. The elastic film 51 is made of elastic material. When the flushing liquid is injected, the flushing liquid flows from the injection head 3 to the locking joint 6, the elastic film 51 is compressed by the flushing liquid, and at this time the first buffer cavity 52 buffers the compression deformation of the elastic film 51; when the injection of the flushing liquid is stopped, the liquid storage container 1 is reset to form a negative pressure in the container cavity 11, the elastic film 51 is partially or completely restored to its original state by its own elasticity and the negative pressure in the container cavity 11, and the flushing liquid is pushed to flow from the injection head 3 to the locking joint 6, thereby preventing the backflow of the flushing liquid, and further preventing the backflow of blood causing the catheter to be blocked.

[0053] Continue to refer to Figure 1The outer wall of the joint side wall 61 is extended outwardly near the middle position to form a pressing auxiliary part 611 for assisting the hand to press the container bottom wall 13 of the liquid storage container 1 away from the end of the injection head 3, so that the flushing liquid in the container cavity 11 is injected from the injection head 3.

[0054] With reference to the first embodiment, Figure 2 The device further comprises a sealing part 8 for blocking the locking joint 6 to prevent the flushing liquid in the container cavity 11 from leaking from the locking joint 6 before the device is used. Optionally, the sealing part 8 is a sealing cap which is sealingly connected with the locking joint 6; or, with reference to the second embodiment, Figure 6 The sealing part 8 is a part of the locking joint 6, and a flat head is formed by heat sealing the end of the locking joint 6 away from the injection head 3; or, with reference to the third embodiment, Figure 1 The sealing part 8 is a heat sealing film which is heat sealed with the end of the locking joint 6 away from the injection head 3. The sealing part 8 shown in the above Figure 1 、 Figure 2 and Figure 6 is only a schematic diagram, and in actual use, the sealing part 8 needs to be removed from the locking joint 6.

[0055] With reference to the first embodiment, Figure 2 and Figure 11 The second embodiment of the pre-filled syringe provided by the utility model has basically the same structure as the first embodiment, and the difference between the two embodiments is that:

[0056] As shown in the first embodiment, Figure 2 and Figure 11 Optionally, the resistance increasing mechanism 4 is an elastic strip 42 arranged between the pressure valve 2 and the injection head 3. The elastic strip 42 is a strip which is attached to the pressure valve 2 at one end of the liquid storage container 1. The elastic strip 42 applies a force to resist the deformation of the pressure valve 2, increases the resistance of the pressure valve 2 to open in the direction of the one end of the liquid storage container 1, and prevents the pressure valve 2 from deforming in the direction of the one end of the liquid storage container 1, so as to prevent the backflow of the flushing liquid and avoid the backflow of the blood to cause the blockage of the catheter. Preferably, the resistance increasing mechanism 4 is a plurality of elastic strips 42 which are arranged in a cross arrangement, a horizontal interval arrangement or a vertical interval arrangement. The elastic strips 42 apply forces to resist the deformation of the pressure valve 2, increase the resistance of the pressure valve 2 to open in the direction of the one end of the liquid storage container 1, and prevent the pressure valve 2 from deforming in the direction of the one end of the liquid storage container 1, so as to prevent the backflow of the flushing liquid and avoid the backflow of the blood to cause the blockage of the catheter.

[0057] With reference to the first embodiment, Figure 6 、 Figure 7 、 Figure 8 and Figure 9As shown, the third embodiment of the pre-filled syringe provided by the utility model has the same structure as the first embodiment basically, and the difference between the two is that:

[0058] Reference Figure 6 As the pressure valve 2 needs deformation space in the process of opening, the larger the space is, the easier the deformation is, and the smaller the force required for opening is. Therefore, the resistance increasing mechanism 4 can increase the resistance of the pressure valve 2 to open in the direction of one end of the liquid storage container 1 by limiting the space of the deformation of the pressure valve 2 in the direction of one end of the liquid storage container 1. As shown, Figure 7 Specifically, the resistance increasing mechanism 4 is a section area changing component 43 arranged between the pressure valve 2 and the injection head 3, the section area changing component 43 is arranged on the inner side of the port of the injection head 3, the section area changing component 43 is attached to the pressure valve 2 at one end of the liquid storage container 1, the section area changing component 43 is fixedly connected to the inner side of the port of the injection head 3, the section area changing component 43 is a ring-shaped component, the section area changing component 43 limits the space of the deformation of the pressure valve 2 in the direction of one end of the liquid storage container 1, increases the resistance of the pressure valve 2 to open in the direction of one end of the liquid storage container 1, thereby preventing the backflow of the flushing liquid, and further avoiding the backflow of the blood to cause the blockage of the catheter. Further, the section area changing component 43 is integrally formed with the injection head 3, the structure is simple, easy to realize, and reduces the production cost of the product. As shown, Figure 8 and Figure 9 Optionally, the section area changing component 43 can also be a semi-ring-shaped component or other irregular section component, as long as it can limit the space of the deformation of the pressure valve 2 in the direction of one end of the liquid storage container 1.

[0059] It should be understood that the above specific embodiments of the utility model are only used for illustrative or explanatory purposes of the principle of the utility model, and do not constitute the limitation of the utility model. Therefore, any modification, equivalent replacement, improvement, etc. made without deviating from the spirit and scope of the utility model shall be included in the protection scope of the utility model. In addition, the appended claims of the utility model are intended to cover all changes and modifications falling within the scope and boundary of the appended claims, or the equivalent forms of such scope and boundary.

Claims

1. A prefilled catheter flusher comprising: A liquid storage container (1) capable of storing flushing liquid, an injection head (3) connected to the liquid storage container (1), and a pressure valve (2) connected to the injection head (3), wherein the injection head (3) is communicated with the inner cavity of the liquid storage container (1); characterized in that a resistance increasing mechanism (4) is provided between the pressure valve (2) and the injection head (3), wherein the resistance increasing mechanism (4) increases the resistance of the pressure valve (2) when it opens toward one end of the liquid storage container (1).

2. The prefilled catheter flusher according to claim 1, characterized in that The pressure valve (2) is in the shape of a diaphragm and is provided with a crack (21).

3. The prefilled catheter flusher according to claim 1 or 2, characterized in that: The resistance increasing mechanism (4) limits the deformation space of the pressure valve (2) toward one end of the liquid storage container (1); or, the resistance increasing mechanism (4) applies a force to the pressure valve (2) to resist the deformation of the pressure valve (2).

4. The prefilled catheter flusher according to claim 3, wherein: The resistance increasing mechanism (4) is a hollow elastic sheet (41); or, the resistance increasing mechanism (4) is an elastic strip (42); or, the resistance increasing mechanism (4) is a component (43) with a variable cross-sectional area.

5. The prefilled catheter flusher according to claim 4, characterized in that The component (43) with a changing cross-sectional area is an annular component or a semi-annular component.

6. The prefilled catheter flusher according to claim 4, characterized in that The component (43) with a changing cross-sectional area is an independent component fixedly connected to the injection head (3); or, the component (43) with a changing cross-sectional area is a component integrally formed with the injection head (3).

7. The prefilled catheter flusher according to any one of claims 1-2, 4-6, characterized in that: The invention also comprises a locking joint (6), which is in the shape of a hollow through-tube. The locking joint (6) is connected to an end of the injection head (3) away from the liquid storage container (1), and the pressure valve (2) is pressed between the locking joint (6) and the injection head (3).

8. The prefilled catheter flusher according to claim 7, characterized in that An outwardly extending extrusion auxiliary component (611) is provided on the outer wall of the locking joint (6).

9. The prefilled catheter flusher according to claim 7, characterized in that It also comprises a sealing component (8), and the sealing component (8) is used to seal the locking joint (6).

10. The prefilled catheter flusher according to claim 7, wherein: The locking joint (6) wall has a shoulder (65), and the pressure valve (2) is compressed between the shoulder (65) and the injection head (3).

11. The prefilled catheter flusher according to claim 10, wherein: The inner wall of the shoulder (65) is provided with a limiting platform (651) extending to one end of the pressure valve (2), and the pressure valve (2) is pressed tightly between the limiting platform (651) and the injection head (3).

12. The prefilled catheter flusher according to claim 11, wherein: The inner wall of the shoulder (65) located inside the limiting platform (651) is also provided with a limiting protrusion (652) extending to one end of the pressure valve (2), and the pressure valve (2) is pressed tightly between the limiting platform (651), the limiting protrusion (652) and the injection head (3).

13. The prefilled catheter flusher according to any one of claims 8 to 12, characterized in that: A buffer mechanism (5) is provided between the end of the locking joint (6) away from the injection head (3) and the pressure valve (2). The buffer mechanism (5) is an elastic component. When the flushing liquid flows from the injection head (3) toward the locking joint (6), the buffer mechanism (5) is compressed; when the flushing liquid stops flowing, the buffer mechanism (5) partially or completely returns to its original state.

14. The prefilled catheter flusher according to claim 13, wherein: The buffer mechanism (5) is an elastic portion provided on the inner wall of the locking joint (6); or, the buffer mechanism (5) is an elastic membrane (51) provided on the inner wall of the locking joint (6), and a first buffer cavity (52) for deformation of the buffer elastic membrane (51) provided on the inner wall of the locking joint (6); or, the buffer mechanism (5) is an elastic protrusion (53) provided on the inner wall of the locking joint (6); or, the buffer mechanism (5) is a non-enclosed air chamber (54) provided on the inner wall of the locking joint (6).

15. The prefilled catheter flusher according to any one of claims 1-2, 4-6, 8-12, and 14, characterized in that: The volume of the liquid storage container (1) can be changed.

16. The prefilled catheter flusher according to any one of claims 1-2, 4-6, 8-12, and 14, characterized in that: The liquid storage container (1) is a bellows that can be expanded and contracted in the longitudinal direction; or, the liquid storage container (1) is a liquid storage bag that can be squeezed and deformed.

17. The prefilled catheter flusher according to any one of claims 1-2, 4-6, 8-12, and 14, characterized in that: The diameter of the end of the liquid storage container (1) away from the injection head (3) is larger than the diameter of the end close to the injection head (3); or, the end of the liquid storage container (1) away from the injection head (3) is provided with a pull ring (7) for facilitating hand force application.

18. The prefilled catheter flusher according to any one of claims 1-2, 4-6, 8-12, and 14, characterized in that: The liquid storage container (1) is provided with a container opening (10), and the injection head (3) is fixedly connected to the container opening (10); or, the injection head (3) is an extension of the peripheral wall of the container opening (10).

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