Venous indwelling needle for preventing blood backflow

Abstract

The utility model discloses a venous indwelling needle for preventing blood backflow. The venous indwelling needle comprises a needle seat, a steel needle and a connecting tube, wherein the steel needle and the connecting tube are connected to the needle seat; the needle seat is of a hollow structure; a plug is assembled in a cavity of the needle seat in a telescopic displacement structure; when the plug is retracted backwards in the cavity of the needle seat, the front section of the cavity of the needle seat is emptied, so that the steel needle is communicated with the connecting tube; and when the plug extends forwards in the cavity of the needle seat, the front section of the cavity of the needle seat is filled so as to seal the steel needle and the connecting pipe. According to the venous indwelling needle, the plug stretches forwards or retracts backwards in the cavity structure of the needle seat, a transfusion channel of the steel needle and the connecting pipe is sealed or communicated, venous blood can be effectively prevented from flowing back, stability is good, and the venous indwelling needle has the technical advantages that treatment is not hindered, and blood can be well prevented from flowing back.

Description

Technical Field

[0001] The utility model relates to a medical device used in a medical environment, in particular to a venous indwelling needle for preventing venous blood from flowing back. Background Art

[0002] Intravenous catheters are commonly used medical devices in clinical treatment. They can effectively reduce repeated punctures of patients by needles during clinical infusions, reduce the pain of punctures for patients and the workload of clinical nurses, and are therefore widely used in clinical treatment and nursing.

[0003] Since intravenous catheters need to be reused, they need to be sealed after each infusion. The sealing of intravenous catheters usually involves injecting isotonic saline into the connecting tube of the catheter, flushing the remaining liquid in the catheter into the blood vessel with the isotonic saline, thereby achieving the effect of blocking the infusion channel of the catheter, preventing venous blood from flowing back, and preventing the blood from flowing back from the veins from forming blood clots in the infusion channel of the catheter. The blood clots formed in the infusion channel of the catheter are prone to form thrombi during the next infusion because they cannot be dissolved and absorbed by the fibrinolytic system in time, which poses a major hidden danger to life safety.

[0004] However, since the sealing stability of isotonic saline is relatively poor, the sealing failure is likely to occur with the movement of the patient's limbs, and venous blood reflux often occurs.

[0005] In response to the technical requirements for preventing blood reflux in venous indwelling needles during clinical infusion therapy, the industry has installed a tube-sealing syringe at the end of the needle seat of the venous indwelling needle to seal the venous indwelling needle with the liquid in the tube-sealing syringe, such as the technology named "Hirudin anticoagulant tube-sealing kit for venous indwelling needles" published in Chinese patent documents, publication number CN 102068730 A, publication date May 25, 2011. Although this technology improves the tube-sealing effect to a certain extent, the effect is not good. On the one hand, the indwelling needle structure of this technology is complex, and on the other hand, the phenomenon of poor tube-sealing stability of the tube-sealing liquid still exists, and the venous blood reflux phenomenon still occurs, but it is slowed down due to the dynamic blocking process.

[0006] The industry also uses other indwelling needle technologies to prevent blood backflow, such as the technology published in the Chinese patent literature with the name "A venous indwelling needle capable of preventing blood backflow and blood coagulation", publication number CN 204468877 U, and publication date July 15, 2015. This technology is provided by providing an opening on the puncture needle, and a blood backflow prevention valve that can be opened and closed is connected to the rear side of the opening, and the opening / closing state of the blood backflow prevention valve is controlled by the pressure difference between the inside and outside of the puncture needle. That is: during infusion, the internal pressure of the puncture needle is greater than the external pressure, the blood backflow prevention valve is stretched open and in an open state, and the therapeutic fluid enters the blood vessel through the channel at the blood backflow prevention valve; when the infusion is completed, the external pressure of the puncture needle is greater than the internal pressure, and the blood backflow prevention valve is in a closed state. This technology uses a structure similar to a one-way valve, which can theoretically effectively prevent venous blood backflow, but it is not clinically operational. The specific reasons are as follows:

[0007] 1. The opening state of the anti-return valve requires a certain internal pressure, and the pressure inside the puncture needle will change with the height of the infusion bottle and the change of the infusion flow rate. The pressure in the puncture needle is uncontrollable; when the internal pressure of the puncture needle is equal to / less than the external pressure, the infusion cannot be carried out normally, affecting the patient's treatment;

[0008] 2. Human blood vessels are thin. When the anti-blood backflow valve is in the open state, the blood circulation is blocked in a direction, which can easily cause discomfort to patients and even lead to safety accidents. Utility Model Content

[0009] The technical purpose of the utility model is to provide a venous indwelling needle which does not affect clinical treatment and can well prevent venous blood reflux in view of the particularity of venous indwelling needle in clinical use and the shortcomings of the prior art.

[0010] The technical purpose of the utility model is achieved through the following technical scheme: a venous indwelling needle for preventing venous blood reflux, comprising a needle seat and a steel needle and a connecting tube connected to the needle seat;

[0011] The needle seat is a hollow structure;

[0012] A plug is installed in the cavity of the needle seat in a telescopic displacement structure;

[0013] When the plug is retracted in the cavity of the needle seat, the front section of the cavity of the needle seat is vacated to allow the steel needle and the connecting tube to be connected; when the plug is extended in the cavity of the needle seat, the front section of the cavity of the needle seat is filled to seal the steel needle and the connecting tube.

[0014] The indwelling venous catheter with the above technical measures is provided with a plug that can extend forward / retract backward in the cavity structure of the needle hub. By the forward / retraction of the plug, the passage between the steel needle and the connecting tube is sealed / conducted. When the plug extends forward, it can form a tight fitting relationship with the cavity structure of the needle hub to seal the passage between the steel needle and the connecting tube, effectively preventing the backflow of venous blood. When re-infusion is required, by retracting the plug, the passage between the steel needle and the connecting tube is conducted. Its structure is simple, the effect of preventing the backflow of venous blood is good, it does not affect normal infusion treatment, and the controllability is strong.

[0015] The plug is assembled in the cavity of the needle hub with an elastic telescopic displacement structure.

[0016] A first telescopic spring is assembled between the rear end of the plug and the rear end of the cavity. The released first telescopic spring pushes the plug forward to fill the front section of the cavity of the needle hub.

[0017] A limiting structure for restricting the retraction structure of the plug is connected to the needle hub.

[0018] The indwelling venous catheter with the above technical measures controls and pre-tightens the forward movement of the plug through the first telescopic spring assembled between the rear end of the plug and the rear end of the cavity, ensuring that the forward-extended plug can seal the steel needle and the connecting tube more tightly and stably.

[0019] Two chutes are spaced circumferentially on the needle hub, and each chute is formed along the axial direction of the needle hub.

[0020] Correspondingly, the rear end of the plug has a slider extending out of the corresponding chute on the needle hub.

[0021] Outside the needle hub, a limiting buckle is hinged corresponding to each chute. A second telescopic spring is assembled between the rear end of the limiting buckle and the needle hub. The second telescopic spring acts like a seesaw with the hinge point in the compressed or released state. The inner side of the front end of the limiting buckle has a convexly formed limiting tooth. When the plug retracts in place, the limiting tooth of the limiting buckle grabs the front edge of the slider of the plug.

[0022] The indwelling venous catheter with the above technical measures fixes the retracted slider of the plug in the chute by the limiting buckle hinged corresponding to each chute outside the needle hub to restrict its relative position during unsealing, making the conduction of the plug to the steel needle and the connecting tube more stable.

[0023] When the plug extends forward in place in the cavity of the needle hub, the front end of the limiting buckle abuts against the bottom end of the plug. For the indwelling venous catheter with this technical measure, the limiting buckle abuts against and limits the slider of the plug in the chute, effectively preventing the accidental collision and unsealing of the plug under non-manipulation, making the sealing of the plug to the steel needle and the connecting tube more stable.

[0024] Between the rear end of the plug and the rear end of the cavity of the needle seat, there are respectively formed guiding cylinders with a hollow structure, which are sleeved and matched and surround the first telescopic spring. For the venous indwelling needle with this technical measure, through the guiding cylinders with a hollow structure, which are sleeved and matched and surround the first telescopic spring, between the rear end of the plug and the rear end of the cavity of the needle seat, the forward / backward displacement process of the plug under the action of the first telescopic spring is stably guided, so that the acting force of the first telescopic spring on the plug is always guaranteed to be in the same axial direction.

[0025] The front end of the plug is a flexible silicone structure. This technical measure of the plug can effectively pre-tighten when blocking the steel needle and the connecting tube, thus forming a denser blockage.

[0026] The front end of the plug is a spherical crown surface structure in the free state;

[0027] Correspondingly, the front end of the cavity of the needle seat is a spherical crown surface structure. The steel needle on the needle seat is connected to the front end of the spherical crown surface of the cavity of the needle seat, and the connecting tube on the needle seat is connected to the side wall of the spherical crown surface of the cavity of the needle seat.

[0028] For the venous indwelling needle with the above technical measures, based on the tightness of the plug with the spherical crown surface structure, it can thus tightly block the steel needle and the connecting tube on the matching needle seat.

[0029] The beneficial technical effects of the present utility model are as follows: The venous indwelling needle of the present utility model seals off / conducts the channels of the steel needle and the connecting tube through the forward / backward movement of the plug in the cavity structure of the needle seat, which neither hinders the treatment nor can effectively prevent the backflow of venous blood, reducing the possibility of blood clots entering the human organs with the next infusion to form thrombus, and has the technical characteristics of good sealing tightness and high sealing stability. Description of the Drawings

[0030] Figure 1 It is a schematic diagram of the non-infusion state of the present utility model.

[0031] Figure 2 It is a schematic diagram of the infusion state of the present utility model.

[0032] The meanings of the codes in the figure: 1 - needle seat; 11 - chute; 2 - steel needle; 3 - connecting head; 4 - plug; 41 - slider; 5 - first telescopic spring; 6 - limit buckle; 61 - limit tooth; 7 - second telescopic spring; 8 - guiding cylinder. Detailed Embodiments

[0033] The present utility model relates to medical instruments used in a medical environment, specifically a venous indwelling needle for preventing the backflow of venous blood. The following is combined with the specification drawings - that is Figure 1 and Figure 2Clearly and detailedly explain the technical solution content of the present utility model.

[0034] It should be specifically noted here that the attached drawings of the present utility model are schematic. In order to clarify the technical purpose of the present utility model, unnecessary details have been simplified to avoid obscuring the technical solution contributed by the present utility model to the prior art. In addition, expressions such as "about" and "substantially" regarding quantity or mating relationship in the following text mean that reasonable assembly errors, processing errors, etc. in the industry are allowed, rather than literally expressing absolute quantity or mating relationship.

[0035] See Figure 1 and Figure 2 As shown, a venous indwelling needle for preventing venous blood reflux includes a needle hub 1, a steel needle 2 connected to the aforementioned needle hub, and a connecting tube 3.

[0036] The aforementioned needle hub 1 is of a hollow structure. A plug 4 is assembled in the cavity of the needle hub 1 in a telescopic displacement structure. The front end of the plug 4 is a flexible silicone structure, and the front end of the plug is a spherical crown surface structure in a free state; correspondingly, the front end of the cavity of the needle hub 1 is a spherical crown surface structure.

[0037] The front end of the spherical crown surface of the needle hub 1 is connected to the steel needle 2; the connecting tube 3 is connected to the side wall of the spherical crown surface of the aforementioned needle hub 1.

[0038] Further, when the rear part of the cavity of the aforementioned needle hub 1 retracts, the front section of the cavity of the needle hub 1 is emptied to conduct the steel needle 2 and the connecting tube 3; when the plug 4 extends forward in the cavity of the needle hub 1, the front section of the cavity of the needle hub 1 is filled to isolate the steel needle 2 and the connecting tube 3.

[0039] A first telescopic spring 5 is assembled between the rear end of the aforementioned plug 4 and the rear end of the cavity of the needle hub 1.

[0040] Specifically, between the rear end of the aforementioned plug 4 and the rear end of the cavity of the needle hub 1, guide cylinders 8 with hollow structures, which are sleeved and mated with each other and surround the first telescopic spring, are respectively formed. The guide cylinders 8 play a role in fixing and limiting the first telescopic spring 5, ensuring that the acting force of the first telescopic spring 5 on the plug 4 is always ensured in the same axial direction.

[0041] When the released first telescopic spring 5 pushes the aforementioned plug 4 forward to fill the front section of the cavity of the needle hub 1.

[0042] A limiting structure for restricting the rearward retraction structure of the aforementioned plug 4 is connected to the needle hub 1.

[0043] Specifically, two chutes 11 are spaced apart in the circumferential direction of the aforementioned needle hub 1. Each chute 11 is formed along the axial direction of the needle hub 1. Correspondingly, the rear end of the aforementioned plug 4 has sliding blocks 41 extending out of the corresponding chutes 11 on the needle hub 1.

[0044] Outside the above-mentioned needle seat 1, a limit buckle 6 is hinged corresponding to each chute 11. A second telescopic spring 7 is assembled between the rear end of the limit buckle 6 and the needle seat 1. The second telescopic spring 7 acts like a seesaw with the hinge fulcrum in a compressed or released state; the inner side of the front end of the limit buckle 6 has a convexly formed limit tooth 61.

[0045] Further, when the plug 4 reaches the rear position, the limit tooth 61 of the limit buckle 6 catches on the front edge of the slider 41 of the plug 4.

[0046] When the plug 4 extends forward to the in-place position in the cavity of the needle seat 1, the front end of the limit buckle 6 abuts against the bottom end of the plug 4.

[0047] Therefore, in order to ensure the stability of the cooperation between the slider 41 of the plug 4 and the limit buckle 6 and prevent flexible deformation, the main structure of the plug 4, or the structure where the slider 41 is located, is formed by a hard structure. Of course, the plug can also be entirely formed of the same material with a high hardness and not easily deformed.

[0048] The above specific technical solutions are only used to illustrate the present invention, rather than to limit it.

[0049] Although the present invention has been described in detail with reference to the above specific technical solutions, those of ordinary skill in the art should understand that they can still modify the above various technical solutions, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the present invention.

Claims

1. An intravenous indwelling needle for preventing blood reflux, comprising a needle hub (1), a steel needle (2) connected to the needle hub, and a connecting tube (3); It is characterized in that: The needle hub (1) has a hollow structure; A plug (4) is assembled in the cavity of the needle hub (1) with a telescopic displacement structure; When the plug (4) retracts in the cavity of the needle hub (1), the front section of the cavity of the needle hub (1) is emptied, so that the steel needle (2) is communicated with the connecting tube (3); when the plug (4) extends forward in the cavity of the needle hub (1), the front section of the cavity of the needle hub (1) is filled to isolate the steel needle (2) from the connecting tube (3); The plug (4) is assembled in the cavity of the needle hub (1) with an elastic telescopic displacement structure; A first telescopic spring (5) is assembled between the rear end of the plug (4) and the rear end of the cavity. The released first telescopic spring (5) pushes the plug (4) forward to fill the front section of the cavity of the needle hub (1).

2. The intravenous indwelling needle for preventing blood reflux according to claim 1, characterized in that: A limiting structure for restricting the retraction structure of the plug (4) is connected to the needle hub (1).

3. The intravenous indwelling needle for preventing blood reflux according to claim 2, characterized in that: Two chutes (11) are spaced circumferentially on the needle hub (1), and each chute (11) is formed along the axial direction of the needle hub (1); Correspondingly, the rear end of the plug (4) has a slider (41) extending out of the corresponding chute (11) on the needle hub (1); Outside the needle hub (1), a limiting buckle (6) is hinged corresponding to each chute (11). A second telescopic spring (7) is assembled between the rear end of the limiting buckle (6) and the needle hub (1). The second telescopic spring (7) makes a seesaw movement with the hinge point in the compressed or released state; a limiting tooth (61) is formed by protruding on the inner side of the front end of the limiting buckle (6). When the plug (4) retracts in place, the limiting tooth (61) of the limiting buckle (6) grabs the front edge of the slider (41) of the plug (4).

4. The intravenous indwelling needle for preventing blood reflux according to claim 3, characterized in that: When the plug (4) extends forward in the cavity of the needle hub (1) in place, the front end of the limiting buckle (6) abuts against the bottom end of the plug (4).

5. The intravenous indwelling needle for preventing blood reflux according to claim 2, characterized in that: Between the rear end of the plug (4) and the rear end of the cavity of the needle hub (1), a guiding cylinder (8) with a hollow structure, which is sleeved and matched and surrounds the first telescopic spring, is formed respectively.

6. The intravenous indwelling needle for preventing blood reflux according to claim 1, characterized in that: The front end of the plug (4) is a flexible silica gel structure.

7. The intravenous indwelling needle for preventing blood reflux according to claim 6, characterized in that: The front end of the plug (4) is a spherical crown surface structure in the free state; Correspondingly, the front end of the cavity of the needle holder (1) is a spherical crown surface structure. The steel needle (2) on the needle holder (1) is connected to the front end of the spherical crown surface of the cavity of the needle holder (1), and the connecting pipe (3) on the needle holder (1) is connected to the side wall of the spherical crown surface of the cavity of the needle holder (1).

Images