CN210904406U

CN210904406U - Infusion set

Info

Publication number: CN210904406U
Application number: CN201920944672.6U
Authority: CN
Inventors: 赵倩; 鲁欣怡; 倪雪
Original assignee: Sichuan Cancer Hospital
Current assignee: Sichuan Cancer Hospital
Priority date: 2019-06-21
Filing date: 2019-06-21
Publication date: 2020-07-03
Anticipated expiration: 2029-06-21

Abstract

The utility model relates to an infusion set, which comprises a needle head and a heparin cap matched with the needle head, wherein the needle head comprises a needle seat, a steel needle arranged at one end of the needle seat, a joint arranged at the other end of the needle seat and a sleeve which wraps the steel needle and is fixed on the needle seat; the heparin cap comprises a guide rod matched with the sleeve, a connecting seat arranged at one end of the guide rod and sealing rubber arranged at the other end of the guide rod, wherein a groove is formed in the connecting seat, an internal thread is arranged in the groove, a channel is formed in the guide rod, and the groove is communicated with the channel; the inner diameter of the sleeve is larger than or equal to the outer diameter of the guide rod, and the guide rod is inserted into the sleeve to realize the detachable connection of the needle head and the heparin cap; the infusion set has the advantages of compact structure and low cost, can effectively avoid needle-stick injuries, not only can automatically align to the center of the heparin cap when in connection, but also has consistent depth of inserting the heparin cap, and the connection between the needle head and the heparin cap is not easy to fall off.

Description

Infusion set

Technical Field

The utility model relates to the technical field of medical equipment, concretely relates to infusion external member.

Background

The needle head is a common instrument in the medical field, such as the needle head arranged on an infusion apparatus; before the needle head commonly used in the prior art is not used, a separately manufactured needle cap is usually required to cover the needle head so as to protect the needle head and avoid needle-stick injuries before the needle head is used; when the medical transfusion needle is used, medical staff need to take off the needle cap to expose the needle head, and then insert the needle head into the corresponding heparin cap to realize communication, so that transfusion can be performed; after the infusion is finished, the medical staff needs to pull out the needle head from the heparin cap, at the moment, the needle cap is not allowed to be reused to cover the needle head generally, because in the process, the needle-stick injury accident is easier to occur, so that the needle head after being used is usually in a non-isolated state, a large potential safety hazard exists, and the needle-stick injury accident is very easy to occur.

In order to avoid needle-stick injuries, for the needle head used for injection, a common means in the prior art is to arrange a movable needle cap on the needle head, when the needle head is not used, the movable needle cap wraps the needle head (namely a steel needle), when the needle head is needed, the movable needle cap can move relative to the needle head in a moving mode, a rotating mode and the like under the action of external force, so that the needle head is exposed for use; after the needle is used, the movable needle cap can be restored to the initial position under the action of external force, so that the needle head is isolated, and the effect of preventing needle stick injuries is achieved; for example, the safety injection needle disclosed in chinese patent CN106730172A has the problems of complicated structure and high cost, and is not suitable for being installed on a needle for infusion, so that the needle for infusion in the prior art usually has a high risk of needle stick, and is easy to cause needle stick injury accidents, and for the existing needle for infusion, there are some disadvantages: 1. the connection process of the needle head and the heparin cap is troublesome and long, and medical staff needs to take great care to align the needle head to the heparin cap and smoothly insert the needle head into the heparin cap to realize communication; 2. when the needle head and the heparin cap are connected, the medical staff also needs to carefully control the insertion depth, and the insertion depth is too deep or too shallow, which is not beneficial to transfusion; 3. the connection between syringe needle and the heparin cap drops easily, and after the heparin cap was connected well with the syringe needle, still need to carry out the repetition fixed usually, and is very troublesome.

SUMMERY OF THE UTILITY MODEL

For solving existence among the prior art, the syringe needle that the infusion was used takes place the needle stick accident easily, and is not convenient for aim at and connect the problem of heparin cap, the utility model discloses the technical scheme who adopts is:

an infusion set comprises a needle head and a heparin cap matched with the needle head, wherein the needle head comprises a needle seat, a steel needle arranged at one end of the needle seat, a connector arranged at the other end of the needle seat and a sleeve wrapping the steel needle and fixed on the needle seat;

the heparin cap comprises a guide rod matched with the sleeve, a connecting seat arranged at one end of the guide rod and sealing rubber arranged at the other end of the guide rod, wherein a groove is formed in the connecting seat, an internal thread is formed in the groove, a channel is formed in the guide rod, and the groove is communicated with the channel;

the inner diameter of the sleeve is larger than or equal to the outer diameter of the guide rod, and the guide rod is inserted into the sleeve to detachably connect the needle head and the heparin cap. In the scheme, the sleeve is fixedly connected outside the needle head for transfusion, the steel needle can be wrapped in the sleeve, the steel needle can be prevented from being polluted, and the needle-prick injury accident can be effectively avoided both before the needle head is used and after the needle head is used; in the scheme, the heparin cap can be detachably fixed at one end of a certain section of the infusion line through the connecting seat, such as at one end of the venous indwelling needle, and the needle head can be arranged at one end of another section of the infusion line, such as at one end of an infusion apparatus; when carrying out venous transfusion, the needle is kept somewhere to the vein and is fixed on one's body the patient, and the heparin cap exposes outside to connect the transfusion system, the one end and the liquid medicine of transfusion system are linked together, through the cooperation of sleeve with the guide bar, and utilize the guide effect of guide bar, the syringe needle can be under the effect of external force fast and accurate insert the central point department of putting of heparin cap, with the quick intercommunication of realization syringe needle and heparin cap, not only easy operation, moreover consuming time weak point.

Preferably, the length of the guide bar is greater than or equal to the depth of the sleeve.

Further, the needle holder also comprises a needle handle, and the needle handle is fixed on the needle holder.

Preferably, the channel is of a trumpet-like configuration.

For the degree of depth that control syringe needle inserted the liver cap element, avoid medical personnel to control according to the experience, in preferred scheme, the tip of steel needle is provided with the location boss, the distance between the terminal surface of location boss and the sleeve terminal surface equals the distance between sealing rubber's terminal surface and the connecting seat. In the process of inserting the syringe needle into the heparin cap, when the steel needle inserted in place, the terminal surface of location boss just in time contacted sealing rubber's terminal surface, sleeve terminal surface just in time contacted connecting seat, reached the restriction steel needle and continued male purpose to make the degree of depth that the steel needle inserted the heparin cap at every turn unanimous, both favorable to the infusion, can avoid medical personnel to control according to the experience again, medical personnel's that can significantly reduce work load.

In order to conveniently and firmly fix the sealing rubber at one end of the guide rod, in a further scheme, one end of the guide rod, which is far away from the connecting seat, is provided with an annular notch, an annular bulge is arranged in the annular notch, and the sealing rubber sleeve is arranged in the annular notch and is fixed on the annular notch through an elastic fixing ring. When assembling, can overlap sealing rubber in annular notch earlier, because annular bellied existence, can make the sealing rubber of annular bulge department take place elastic deformation to compress tightly annular bulge, then set up the elastic fixation circle in sealing rubber's the outside, make sealing rubber can compress tightly in annular notch, thereby realize firm fixed to sealing rubber, be difficult to drop in the use that relapses.

In order to prevent the needle head and the heparin cap from falling off in the using process, the heparin cap locking device further comprises a locking device used for locking the sleeve, the locking device comprises an elastic pressing sheet and a locking hole formed in the side wall of the sleeve, notches are formed in the connecting seat and the guide rod, the elastic pressing sheet is arranged in the notches, one end of the elastic pressing sheet is fixed in the connecting seat, the other end of the elastic pressing sheet radially extends out of the notches along the guide rod to form a spring bolt, and the spring bolt is used for being clamped into the locking hole. When the needle head and the heparin cap are connected, the heparin cap is sleeved in the sleeve, then the needle head is pushed along the length direction of the guide rod, under the guiding action of the guide rod, the steel needle can accurately penetrate through the sealing rubber in a labor-saving manner, the communication between the needle head and the heparin cap is realized, at the moment, the lock tongue is just clamped in the lock hole, and the needle head and the heparin cap are locked, so that the problem of accidental falling can be effectively avoided; when syringe needle and heparin cap need be separated, only need pressure elasticity preforming, elasticity preforming warp under the effect of external force for the spring bolt withdraws from the lockhole, and in the shrink groove inlet, thereby separation syringe needle and heparin cap that can be convenient, in the syringe needle after the separation, the steel needle is wrapped up in including by the sleeve all the time, thereby can effectively avoid the acupuncture wound.

In a preferred scheme, the surface of the lock tongue, which is far away from the connecting seat, is an arc-shaped surface and is used for guiding the elastic pressing sheet clamped into the lock hole.

In a preferred scheme, the locking device comprises two locking devices, and the elastic pressing sheets in the two locking devices are respectively arranged on the connecting seat in a mutually symmetrical mode. The unlocking device is more convenient and labor-saving to operate during unlocking.

Furthermore, the connecting seat further comprises a pressing plate, and the pressing plate is fixed on the elastic pressing plate at a position far away from the side face of the connecting seat. The clamp plate is used for increasing the area of contact that medical personnel pointed when the unblock to when the unblock, medical personnel are through the extrusion clamp plate, unblock that just can be convenient, and is also more laborsaving simultaneously.

In order to better fix the infusion set, especially when the infusion set is arranged on a CVC (composite container connector), and to facilitate the infusion set to fall off accidentally in the using process, in a further scheme, a hanging ring for connecting a pin is arranged on the side surface of the connecting seat, and/or a through hole for connecting the pin is arranged on the needle handle.

In a preferred scheme, the intravenous infusion set further comprises a venous indwelling needle and an infusion set, wherein the heparin cap is communicated with a positive pressure connector in the venous indwelling needle through the connecting seat, and the needle head is communicated with an infusion hose in the infusion set through the connector.

In another preferred scheme, the disposable infusion set further comprises a venous catheter, an extension catheter, a positive pressure connector and an infusion set, wherein the venous catheter and the positive pressure connector are respectively arranged at two ends of the extension catheter, the heparin cap is communicated with the positive pressure connector through the connecting seat, and the needle is communicated with an infusion hose in the infusion set through the connector.

Compared with the prior art, the utility model provides a pair of infusion external member has following beneficial effect:

1. the infusion set has compact structure and low cost, and can effectively avoid needle-stick injuries.

2. This infusion external member can aim at the center of heparin cap when connecting automatically, and insert the degree of depth unanimous of heparin cap to be favorable to syringe needle and heparin cap to realize quick, accurate being connected, medical personnel's that can significantly reduce work load.

3. This infusion external member is provided with locking device for in infusion process, the connection between syringe needle and the heparin cap is more difficult to drop.

4. The infusion set is suitable for indwelling needle infusion, CVC infusion, PICC infusion and the like, and has a wide application range.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a schematic structural view of a needle of an infusion set provided in embodiment 1 of the present invention.

Fig. 2 is a schematic structural view of a heparin cap in an infusion set provided in embodiment 1 of the present invention.

Fig. 3 is a cross-sectional view of fig. 2.

Fig. 4 is a schematic structural view of an infusion set provided in embodiment 1 of the present invention after a needle is connected to a heparin cap.

Fig. 5 is a partial structural schematic view of an infusion set provided in embodiment 1 of the present invention.

Fig. 6 is a partial cross-sectional view of fig. 5.

Description of the drawings

A needle head 101, a needle seat 102, a steel needle 103, a joint 104, a needle handle 105, a sleeve 106, a positioning boss 107, a lock hole 108,

the heparin cap 201, the guide rod 202, the channel 203, the connecting seat 204, the groove 205, the internal thread 206, the sealing rubber 207, the annular notch 208, the annular bulge 209, the elastic fixing ring 210, the notch 211, the hanging ring 212,

a locking device 301, an elastic pressing sheet 302, a locking tongue 303, a pressing plate 305,

a positive pressure connector 401, an extension tube 402 and an infusion hose 403.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. The components of embodiments of the present invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiment of the present invention, all other embodiments obtained by the person skilled in the art without creative work belong to the protection scope of the present invention.

Example 1

Referring to fig. 1-6, the present embodiment provides an infusion set, including a needle 101, a heparin cap 201 adapted to the needle 101, wherein the needle 101 includes a needle holder 102, a steel needle 103 disposed at one end of the needle holder 102, a connector 104 disposed at the other end of the needle holder 102, and a sleeve 106 covering the steel needle 103 and fixed to the needle holder 102;

the heparin cap 201 comprises a guide rod 202 matched with the sleeve 106, a connecting seat 204 arranged at one end of the guide rod 202, and sealing rubber 207 arranged at the other end of the guide rod 202, wherein a groove 205 is arranged in the connecting seat 204, an internal thread 206 is arranged in the groove 205 so as to be connected with a common positive pressure connector 401, a channel 203 is arranged in the guide rod 202, and the groove 205 is communicated with the channel 203;

the inner diameter of the sleeve 106 is larger than or equal to the outer diameter of the guide rod 202, and the guide rod 202 is inserted into the sleeve 106 to realize the detachable connection of the needle 101 and the heparin cap 201. In the scheme, the sleeve 106 is fixedly connected outside the needle head 101 for transfusion, the steel needle 103 can be wrapped in the sleeve 106, the steel needle 103 can be prevented from being polluted, and needle-prick accidents can be effectively avoided both before the needle head 101 is used and after the needle head 101 is used; in the scheme, the heparin cap 201 can be detachably fixed at one end of a certain section of the infusion line through the connecting seat 204, for example, at one end of a venous indwelling needle, a PICC catheter or a CVC catheter, and the needle 101 can be arranged at one end of another section of the infusion line, for example, at one end of an infusion apparatus; the venous indwelling needle is fixed on a patient, the heparin cap 201 is exposed outside so as to be connected with an infusion apparatus, one end of the infusion apparatus is communicated with liquid medicine, when venous infusion is carried out, medical workers can sleeve the heparin cap 201 into the sleeve 106 through the matching of the sleeve 106 and the guide rod 202, then push the needle head 101 along the length direction of the guide rod 202, under the guiding action of the guide rod 202, the steel needle 103 can accurately, labor-saving and quickly penetrate through the sealing rubber 207, so that the communication between the needle head 101 and the heparin cap 201 is realized, and at the moment, the steel needle 103 is accurately inserted into the central position of the heparin cap 201 so as to be convenient for infusion; after the infusion is completed, the needle head 101 and the heparin cap 201 can be manually separated, the separated steel needle 103 is always positioned in the sleeve 106, the needle stick injury can be effectively avoided, the sleeve 106 can be used for collecting the medicine overflowing from the steel needle 103, and the residual medicine liquid at the steel needle 103 can be effectively prevented from flowing outwards or dripping to pollute the environment.

In addition, it can be understood that in the present embodiment, the communication between the heparin cap 201 and the needle 101 is realized by the cooperation of the guide rod 202 and the sleeve 106, so that the length of the steel needle 103 in the needle 101 can be greatly shorter than the length of the steel needle 103 commonly used in the prior art, and the cost can be greatly reduced.

In a preferred embodiment, the length of the guide rod 202 may be greater than or equal to the depth of the sleeve 106.

As shown in fig. 1, 4 or 5, in a further embodiment, the medical needle further includes a needle handle 105, and the needle handle 105 is fixed to the needle seat 102 to facilitate the holding operation of the medical staff.

In a preferred embodiment, as shown in fig. 3 or fig. 6, the channel 203 has a trumpet-shaped structure to guide the liquid medicine.

In order to control the depth of the needle 101 inserted into the heparin cap and avoid the control of medical staff according to experience, in a preferred scheme, the end of the steel needle 103 is provided with a positioning boss 107, and the distance between the end face of the positioning boss 107 and the end face of the sleeve 106 is equal to the distance between the end face of the sealing rubber 207 and the connecting seat 204. In the process of inserting the needle head 101 into the heparin cap 201, when the steel needle 103 is inserted in place, the end surface of the positioning boss 107 just contacts with the end surface of the sealing rubber 207, and the end surface of the sleeve 106 just contacts with the connecting seat 204, as shown in fig. 4 or fig. 6, so that the purpose of limiting the steel needle 103 to be inserted continuously is achieved, the depth of the steel needle 103 inserted into the heparin cap 201 every time is consistent, the infusion is facilitated, the medical care personnel can be prevented from controlling according to experience, and the workload of the medical care personnel can be greatly reduced.

In order to conveniently and firmly fix the sealing rubber 207 at one end of the guide rod 202, in a further aspect, an annular notch 208 is formed at one end of the guide rod 202 away from the connecting seat 204, an annular protrusion 209 is formed in the annular notch 208, and the sealing rubber 207 is sleeved in the annular notch 208 and fixed to the annular notch 208 by an elastic fixing ring 210. As shown in fig. 3, 4 or 6, when assembling, the sealing rubber 207 may be firstly sleeved in the annular notch 208, due to the existence of the annular protrusion 209, the sealing rubber 207 at the annular protrusion 209 may be elastically deformed so as to press the annular protrusion 209, then the elastic fixing ring 210 is disposed at the outer side of the sealing rubber 207, the elastic fixing ring 210 may be made of a plastic film, so that the sealing rubber 207 may be pressed in the annular notch 208, thereby realizing firm fixation of the sealing rubber 207, and being not easy to fall off in a repeated use process.

In order to prevent the connection between the needle 101 and the heparin cap 201 from falling off during use, in a further embodiment, the locking device 301 is further included for locking the sleeve 106, the locking device 301 includes an elastic pressing piece 302 and a locking hole 108 disposed on a side wall of the sleeve 106, as shown in fig. 2, 3, 4, or 6, notches 211 are disposed on the connecting seat 204 and the guide rod 202, the elastic pressing piece 302 is disposed in the notch 211, one end of the elastic pressing piece 302 is fixed to the connecting seat 204, the other end of the elastic pressing piece 302 extends out of the notch 211 along a radial direction of the guide rod 202 to form a locking tongue 303, and the locking tongue 303 is used for being snapped into the locking hole 108. When the needle head 101 and the heparin cap 201 are connected, the heparin cap 201 is sleeved into the sleeve 106, then the needle head 101 is pushed along the length direction of the guide rod 202, the steel needle 103 can accurately and labor-effectively penetrate through the sealing rubber 207 under the guiding action of the guide rod 202, the communication between the needle head 101 and the heparin cap 201 is realized, at the moment, the lock tongue 303 is just clamped into the lock hole 108, and the needle head 101 and the heparin cap 201 are locked, so that the problem of accidental falling can be effectively avoided; when needs separation syringe needle 101 and heparin cap 201, only need pressure elasticity preforming 302, elasticity preforming 302 warp under the effect of external force for bolt 303 withdraws from the lockhole 108, and contracts into in the notch 211, thereby separation syringe needle 101 and heparin cap 201 that can be convenient, in the syringe needle 101 after the separation, steel needle 103 is wrapped up including by sleeve 106 all the time, thereby can effectively avoid the needle to hinder.

In order to facilitate the sliding of the latch tongue 303 into the latch hole 108, the latch hole 108 preferably has an elongated structure and is distributed along the circumferential direction of the sleeve 106, as shown in fig. 4 or 5.

In this embodiment, the elastic pressing plate 302 may be made of a plastic material, as shown in fig. 3, one end of the elastic pressing plate 302 may be directly fixed to the connecting seat 204, and both the connecting seat 204 and the guiding rod 202 may be made of a material.

As shown in fig. 3 or fig. 6, in a preferred embodiment, a surface of the latch 303 away from the connecting seat 204 is an arc surface for guiding the elastic pressing piece 302 to be locked into the locking hole 108.

As shown in fig. 2, fig. 3, fig. 4, and fig. 5, in a further aspect, the connecting device further includes a pressing plate 305, and the pressing plate 305 is fixed on the elastic pressing plate 302 at a position away from the side surface of the connecting seat 204. The clamp plate 305 is used for increasing the contact area of the fingers of the medical staff when unlocking, so that the medical staff can conveniently unlock the lock through extruding the clamp plate 305 when unlocking, and simultaneously, the labor is saved.

As shown in fig. 2, fig. 3, fig. 4, or fig. 5, in a preferred embodiment provided in this embodiment, two locking devices 301 are included, and the elastic pressing pieces 302 in the two locking devices 301 are respectively and symmetrically arranged on the connecting seat 204, as shown in the figure, the two locking devices 301 are respectively arranged in the opposite directions of the circumference of the connecting seat 204, and when unlocking, the medical staff only needs to press the two pressing plates 305 at the same time to unlock, so that the operation is more convenient and labor-saving when unlocking.

In a more perfect scheme, in order to better fix the infusion set, especially to facilitate the infusion set to be accidentally disconnected or fall off during use when the infusion set is arranged on a CVC, in a further scheme, a hanging ring 212 for connecting a pin is arranged on the side surface of the connecting seat 204, and/or a through hole for connecting the pin is arranged on the needle handle 105; as shown in fig. 2 and fig. 5, for example, in the embodiment, a hanging ring 212 for connecting a pin is disposed on a side surface of the connecting seat 204, and in an actual use process, the pin can penetrate through the hanging ring 212 and hang the heparin cap 201 on surrounding clothes, so that the falling off under the action of an external force can be effectively avoided.

Example 2

The infusion set provided by the present embodiment includes a venous indwelling needle and an infusion set, wherein the heparin cap 201 described in embodiment 1 is communicated with a positive pressure connector 401 in the venous indwelling needle through the connecting seat 204, and the needle 101 described in embodiment 1 is communicated with an infusion hose 403 in the infusion set through the connector 104, as shown in fig. 5 and 6. When in use, the venous indwelling needle is communicated with an infusion apparatus through the matching of the needle head 101 and the heparin cap 201, so that the infusion can be conveniently carried out.

As can be understood by those skilled in the art, the venous indwelling needle generally comprises a positive pressure connector 401, an extension tube 402, a first clamping switch for controlling the on/off of the extension tube 402, an indwelling needle head, wherein the positive pressure connector 401 and the indwelling needle head are respectively arranged at two ends of the extension tube 402, and the heparin cap 201 is detachably connected to the positive pressure connector 401 through threads so as to be communicated with an infusion apparatus;

the infusion apparatus generally comprises a bottle stopper puncture outfit, an infusion hose 403, a drip cup, a flow regulator and a second clamping switch for controlling the on/off of the infusion hose 403, wherein the bottle stopper puncture outfit and the needle 101 are respectively arranged at two ends of the infusion hose 403, and the drip cup and the flow regulator are respectively arranged on the infusion hose 403 between the needle 101 and the puncture outfit.

Example 3

The infusion set provided by this embodiment includes an intravenous set tube, an extension tube 402, a positive pressure connector 401 and an infusion set, wherein the intravenous set tube and the positive pressure connector 401 are respectively disposed at two ends of the extension tube 402, the heparin cap 201 described in embodiment 1 is communicated with the positive pressure connector 401 through the connection seat 204, and the needle 101 described in embodiment 1 is communicated with an infusion hose 403 in the infusion set through the connector 104, as shown in fig. 5 and 6. In this embodiment, the intravenous tube, extension tube 402, positive pressure connector 401, and heparin cap 201 described in embodiment 1 constitute a Central Venous Catheter (CVC), and the infusion set may be configured as the infusion set described in embodiment 2.

The above description is only for the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions within the technical scope of the present invention, and all should be covered within the protection scope of the present invention.

Claims

1. An infusion set is characterized by comprising a needle head and a heparin cap matched with the needle head, wherein the needle head comprises a needle seat, a steel needle arranged at one end of the needle seat, a connector arranged at the other end of the needle seat and a sleeve wrapping the steel needle and fixed on the needle seat;

the inner diameter of the sleeve is larger than or equal to the outer diameter of the guide rod, and the guide rod is inserted into the sleeve to detachably connect the needle head and the heparin cap.

2. The infusion set in accordance with claim 1, further comprising a needle handle secured to said needle hub.

3. The infusion set according to claim 1, wherein the end of the steel needle is provided with a positioning boss, and the distance between the end surface of the positioning boss and the end surface of the sleeve is equal to the distance between the end surface of the sealing rubber and the connecting seat.

4. The infusion set as claimed in claim 1, wherein the guide rod is provided with an annular notch at an end thereof remote from the connection seat, the annular notch is provided with an annular protrusion, and the sealing rubber sleeve is disposed in the annular notch and fixed to the annular notch by an elastic fixing ring.

5. The infusion set as claimed in any one of claims 1 to 4, further comprising a locking device for locking the sleeve, wherein the locking device comprises an elastic pressing piece and a locking hole formed in a side wall of the sleeve, notches are formed in the connecting base and the guide rod, the elastic pressing piece is arranged in the notch, one end of the elastic pressing piece is fixed to the connecting base, the other end of the elastic pressing piece extends out of the notch along the radial direction of the guide rod to form a locking tongue, and the locking tongue is used for being clamped into the locking hole.

6. The infusion set as claimed in claim 5, wherein the surface of the latch tongue away from the connecting seat is an arc-shaped surface for guiding the elastic pressing piece to be inserted into the locking hole.

7. The infusion set as claimed in claim 5, further comprising a pressure plate fixed to the resilient pressure plate at a position away from the side of the connection holder.

8. The infusion set as claimed in claim 5, wherein two locking devices are included, and the elastic pressing pieces of the two locking devices are symmetrically arranged on the connecting seat.

9. The infusion set as claimed in claim 2, wherein a hanging ring for connecting a pin is provided on a side surface of the connecting seat, and/or a through hole for connecting a pin is provided on the needle handle.

10. The infusion set as claimed in claim 5, further comprising a venous indwelling needle and an infusion set, wherein the heparin cap is communicated with a positive pressure connector in the venous indwelling needle through the connecting base, and the needle is communicated with an infusion hose in the infusion set through the connector; or the intravenous catheter and the positive pressure connector are respectively arranged at two ends of the extension tube, the heparin cap is communicated with the positive pressure connector through the connecting seat, and the needle head is communicated with an infusion hose in the infusion apparatus through the connector.