WO2022027261A1

WO2022027261A1 - Anti-backflow indwelling needle

Info

Publication number: WO2022027261A1
Application number: PCT/CN2020/106922
Authority: WO
Inventors: 陆军; 赵丽杰; 王嘉琦; 倪琳; 陈天柱; 陆维炜
Original assignee: 江苏采纳医疗科技有限公司
Priority date: 2020-08-05
Filing date: 2020-08-05
Publication date: 2022-02-10

Abstract

An anti-backflow indwelling needle, comprising a puncture needle (21), an infusion channel (144) defined by an outer needle seat (14), and a valve assembly for sealing the infusion channel (144), the valve assembly comprises an elastic seal member (13) and a switch assembly for opening the seal member (13), the seal member (13) is in a normally closed state so as to close the infusion channel (144); the switch assembly comprises a fixedly provided stopping member and a movably provided pressing member (12), the pressing member (12) comprises a first part (121a) and a second part (121b) connected to one another, when the first part (121a) of the pressing member (12) receives an external force and moves toward the seal member (13), the second part (121b) abuts against the seal member (13) to enable the seal member (13) to elastically deform at the stopping member so as to open the infusion channel (144), the external force is from a force generated when the indwelling needle cooperates with an infusion device; and when the puncture needle (21) passes through the seal member (13), the infusion channel (144) is not opened. The anti-backflow valve assembly can be opened while a syringe or an infusion tube is installed, operations are simple, and usage is convenient.

Description

Anti-reflux indwelling needle

technical field

The utility model relates to the field of medical devices, in particular to an indwelling needle for preventing backflow.

Background technique

At present, a large number of disposable venipuncture needles are used in blood transfusion and infusion treatment in China, which increases the workload of medical staff and increases the suffering of patients. Compared with ordinary steel needles, the indwelling needle has a longer indwelling time and is softer, which can help to establish a blood transfusion and infusion channel that can be used repeatedly, which can reduce the pain and mental burden caused by repeated puncture to the patient, and can quickly infuse fluid while reducing Nurses' clinical workload is more and more widely used in clinical practice.

The most commonly used straight indwelling needle is in the clinical venipuncture process. The needle tube and the catheter puncture you into the vein together. After the needle tube is pulled out, you must press the front end of the punctured vein with one hand, otherwise blood will flow out. The operation of personnel brings great inconvenience.

In order to solve the problem of blood backflow, the Chinese Utility Model Patent Application No. 200420078043.3: Anti-reverse-flow venous indwelling needle discloses that a pair of anti-reverse-flow valves with linear slits left at the coaptation line are arranged in the cannula seat, so as to prevent Backflow function; and for the convenience of use, a pair of protrusions for extrusion are provided at both ends of the outer wall of the casing seat corresponding to the slits to form an anti-reverse flow switch. However, in actual use, when flushing or infusion is required, after installing a pre-flushing syringe or T-shaped infusion tube, it is necessary to press the protrusion to open the anti-reflux valve before it can be used. The operation steps are cumbersome and inconvenient for medical staff. Use in daily busy work.

Utility model content

The purpose of this utility model is to aim at the above-mentioned defects in the prior art, to provide an anti-reverse flow indwelling needle, which can open the anti-reverse flow valve assembly while installing a syringe or an infusion tube, without the need for additionally setting a drive mechanism to cooperate with the valve assembly, The operation is simple, convenient and quick.

In order to realize the above-mentioned purpose of the utility model, the utility model adopts the following technical solutions:

An anti-reflux indwelling needle, comprising a puncture needle, an infusion channel defined by an outer needle seat, and a valve assembly for sealing the infusion channel, the valve assembly including an elastic seal and a switch assembly for opening the seal , the seal is in a normally closed state to close the infusion channel; the switch assembly includes a fixed stopper and a movably arranged extrusion, the extrusion includes the first part and the The second part, when the first part of the extrusion part receives an external force and moves toward the seal, the second part abuts the seal so that the seal occurs at the stopper The elastic deformation is used to conduct the infusion channel, and the external force comes from the force generated when the indwelling needle cooperates with the infusion device; when the puncture needle passes through the seal, the infusion channel is not conducted.

Optionally, the seal has a normally closed cutout, the cutout opens to allow fluid to pass through when the seal is elastically deformed, and the puncture needle passes through the cutout without causing deformation of the seal Therefore, the infusion channel is not conducted, and the blood will not flow backward during puncture.

Optionally, the sealing member is circular, duckbill or bullet-shaped, the sealing member is elastic, and elastically presses the inner wall of the outer needle seat.

Optionally, both the extrusion piece and the stopper are located in the infusion channel, the extrusion piece and the stopper are distributed on both sides of the seal, and the stopper is used for In order to prevent the axial movement of the sealing member, the first portion of the pressing member is away from the sealing member to cooperate with the infusion device, and the second portion of the pressing member is close to the sealing member.

Optionally, the extrusion part includes a connecting part and a plurality of axially extending arms, the connecting part has the through hole for accommodating the puncture needle to pass through, and the arms include all parts away from the sealing part. The first part and the second part close to the sealing member, a number of the arms are arranged on the outer side of the connecting member, so that the arms are close to the inner wall of the outer needle seat. The extrusion piece can be flexibly arranged in the outer needle seat, and can normally abut with the fitting end of the infusion device, and the structure is simple and reliable.

Optionally, the stopper includes a boss fixedly arranged on the inner wall of the outer needle seat, and the boss forms a block on the edge of the sealing member, so that the sealing member cannot continue to approach the outer surface in the axial direction. Needle.

Optionally, the bosses are provided with two, and the two are axially symmetrical. The number of bosses should not be too large, and the area of the bosses should not be too large. The part contacting the boss will be deformed when being squeezed, and if the boss is too large or the boss area is too large, the effective deformation of the seal cannot be guaranteed, so that the purpose of conducting the infusion channel cannot be achieved.

Optionally, a channel is formed between the side edge of the sealing member after being squeezed and the inner wall of the outer needle seat, as a spare channel to ensure the stability of the use of the anti-reflux indwelling needle.

Optionally, an anti-stab wound safety device is provided in the extrusion part, the puncture needle penetrates the anti-stab wound safety device, and the anti-stab wound safety device is used to extract the infusion channel from the puncture needle. The tip of the puncture needle is covered at the same time, which avoids the harm caused by the puncture to the medical staff and prevents secondary infection.

Optionally, the stab-proof safety device includes a bottom block, a first elastic arm and a second elastic arm connected on both sides of the bottom block, a first elastic piece disposed at the front end of the first elastic arm, and The second elastic piece is arranged at the front end of the second elastic arm, the bottom blocking piece is provided with a through hole for the puncture needle to pass through, and a part of the outer wall of the puncture needle is provided with a limiting protrusion.

Compared with the prior art, the utility model has the advantages of:

During the puncture operation, the closed anti-reverse flow structure formed by the seal and the outer needle tube assembly is used to effectively prevent blood overflow and block the spread of infectious diseases with blood as the transmission route, thereby reducing the incidence of nosocomial infections in patients. Probability; when normal infusion or flushing is required, while installing the syringe or infusion tube, the seal is deformed by pushing out the extruder to cooperate with the boss, and the incision of the seal is opened for effective infusion, the incision The opening speed is fast, the operation is simple, and it is convenient to use.

In addition, after the anti-reverse flow seal is extruded, a channel is formed between its side and the inner wall of the outer needle seat. When the anti-reverse flow seal is very thick and the incision cannot be opened by extrusion deformation, effective infusion can be carried out through the channel. Ensure the stability of the anti-reflux indwelling needle.

In addition, a puncture-proof safety device is set on the puncture needle. When the puncture needle is withdrawn, the anti-needle puncture safety device will be brought out together and completely cover the puncture end, avoiding the harm caused by the puncture to the medical staff and preventing secondary infection. .

Description of drawings

FIG. 1 is a schematic diagram of the structure of the anti-backflow indwelling needle in the present invention.

FIG. 2 is a cross-sectional view of A-A in FIG. 1 .

FIG. 3 is an enlarged schematic view of part C in FIG. 2 .

4 is a schematic structural diagram of another angle of the anti-reverse flow indwelling needle in the present invention.

FIG. 5 is a cross-sectional view of B-B in FIG. 4 .

FIG. 6 is an enlarged schematic diagram of part D in FIG. 5 .

FIG. 7 is a schematic view of the structure of the extrusion part of the present invention.

FIG. 8 is a schematic structural diagram of the anti-stab wound safety device in the present invention.

9 is a schematic structural diagram of another angle of the stab-proof safety device in the present invention.

FIG. 10 is a schematic diagram of the state of the extrusion part extruding the anti-reverse flow sealing part in the present invention.

11 is a schematic diagram of the installation structure of the boss in the present invention.

12 is a schematic diagram of the use state of the stab-proof safety device in the present invention.

Fig. 13 is a schematic view of the structure of the seal in the present invention.

FIG. 14 is another structural schematic diagram of the sealing element in the present invention.

Figure 15 is a schematic structural diagram of the boss in the present invention.

detailed description

The technical solution of the present utility model is further described in non-limiting detail below in conjunction with the preferred embodiments and the accompanying drawings.

As shown in FIG. 1 and FIG. 11 , the anti-reflux indwelling needle of one embodiment includes an outer needle tube assembly, an infusion channel 144 located in the outer needle tube assembly, a puncture needle assembly and a valve assembly. The valve assembly is in the indwelling needle of this embodiment. When it is not connected with the infusion device, it is in the closed state. At this time, the infusion channel 144 is closed by the valve assembly and cannot form a passage, and the fluid cannot flow freely in the infusion channel 144, that is, the doctor or other operators insert the indwelling needle of this embodiment into the blood vessel. When the puncture needle assembly is withdrawn, the blood cannot flow backward through the infusion channel 144; when the indwelling needle of this embodiment is mated with the infusion device, the mating end of the infusion device (syringe or infusion tube) can abut against the valve assembly and force The valve assembly is opened so that the infusion channel 144 is in a conducting state, so that normal infusion work can be performed. Specifically, it will be described in detail below.

As shown in FIG. 11 , the outer needle tube assembly includes an outer needle hub 14 and a needle tube 15 that are fixedly connected to each other. The needle tube 15 and the outer needle hub 14 are in fluid communication, and the outer needle hub 14 is provided with an infusion fluid extending in the direction of the central axis A. Channel 144. The main body part 141, the constricted part 142 and the needle tube connecting part 143 are connected to each other in sequence in the outer needle hub 14. The main body part 141 has a basic cylindrical structure, and the constricted part 142 is a tapered truncated cone-shaped structure. 15 matches.

As shown in Figures 3 and 4, the puncture needle assembly includes a puncture needle 21, a puncture needle base 22 connected to the puncture needle 21, and a puncture needle connection base 23 connected to the puncture needle base 22. The puncture needle 21 enters the outer needle base when the puncture needle 21 enters the outer needle base. At 14, through extrusion 12, seal 13 and back into needle 15.

As shown in FIG. 3 , the valve assembly includes a sealing member 13 and a switch assembly for opening the sealing member 13. The edge of the sealing member 13 elastically presses the inner wall of the outer needle seat 14, so the sealing member 13 is in a normally closed state to close the infusion channel 144, the sealing member 13 is made of elastic material, that is, the sealing member 13 can be bent and deformed when being squeezed by the switch assembly. The switch assembly includes a fixed stopper and a movable extrusion piece 12 , the extrusion piece 12 and the stopper are both located in the infusion channel 144 , and the extrusion piece 12 and the stopper are respectively arranged on the upper and lower sides of the seal 13 . On both sides, the stopper is used to prevent the axial movement of the seal 13. The extrusion 12 includes a first part and a second part. When the first part of the extrusion 12 receives an external force and moves toward the seal 13, the extrusion The second part abuts the sealing member 13 so that the sealing member 13 is elastically deformed at the stopper to conduct the infusion channel 144 .

In an optional embodiment, as shown in FIG. 7 , the extrusion member 12 includes a connecting member 123 and a plurality of arms 121 extending along the direction of the central axis A. The connecting member 123 has a through hole 124 for accommodating the puncture needle 21 to pass through, The arm 121 includes a first part 121 a away from the seal 13 and a second part 121 b close to the seal 13 . Specifically, two arms 121 may be provided, and the two arms 121 are fixed to the outside of the connecting member 123 in an axisymmetric manner. Of course, other numbers of arms 121 may also be provided as required. The shapes of the first portion 121a and the second portion 121b are not limited, as long as the end surfaces of the first portion 121a and the second portion 121b can abut against the infusion device and the sealing member 13, respectively. In the initial state, the first portion 121 a and the second portion 121 b of the arm 121 are located below the sealing member 13 and are not in contact with the sealing member 13 .

As shown in FIG. 6 and FIG. 11 , a bracket 16 for installing the extrusion part 12 is also arranged in the outer needle hub 14 , the bracket 16 is a hollow cylindrical structure, and a part of the upper end of the bracket 16 is built-in and positioned in the main body part 141 , An inwardly extending step 161 is provided on the inner wall of the bracket 16 near the lower end, and the first part 121 a of the arm 121 is supported on the step 161 . It should be noted that the cross-sectional area of the first part 121 a is larger than the cross-sectional area of the step 161 , so that the end face of the first part 121 a protrudes beyond the step 161 , and the entire extrusion part 12 is slidably arranged in the bracket 16 . The bracket 16 can be fixed in the outer needle hub 14 by means of snap-fit or interference fit.

In an optional embodiment, as shown in FIG. 10 and FIG. 15 , the stopper includes a boss 111 fixed on the inner wall of the outer needle hub 14 , the boss 111 extends inside the outer needle hub 14 , and the boss 111 is located at the inner wall of the outer needle hub 14 . Above the seal 13 and close to the edge of the seal 13 . The boss 111 may be disposed in the main body portion 141 of the outer needle hub 14 , or may also be disposed at the junction of the main body portion 141 and the constricted portion 142 . Specifically, two bosses 111 are provided, and they are arranged in a line, that is, symmetrically arranged on the left and right. The part of the sealing member 13 located on the boss 111 is blocked, and the other parts are not blocked. deformed. The number of the bosses 111 can also be set to 3 or 4, but the number should not be too large, to ensure that a sufficient part of the sealing member 13 is not blocked by the bosses 111. The shape of the boss 111 is not limited, as long as it can stop the sealing member 13 . When the infusion device is connected, the fitting of the infusion device can abut the end of the bottom surface of the first part 121a, the arm 121 starts to move toward the seal 13 under the pressing force, and then the second part 121b of the arm 121 begins to squeeze the seal The portion of the sealing member 13 close to the edge causes the edge of the sealing member 13 to deform.

The sealing member 13 includes an elastic body and an incision 131 arranged on the main body, and the incision 131 is a slit structure running through the main body; when the main body is not deformed, the gap is closed, and the opening of the incision 131 is in a closed state, so that the main body can close the infusion channel; After being squeezed and deformed by an external force, the incision 131 is opened, so that the fluid can flow freely in the infusion channel. The position of the incision is close to the middle of the seal 13, so that the puncture needle 21 can pass through it. In an optional embodiment, as shown in FIG. 13 and FIG. 14 , the incision 131 is in a straight shape or a plurality of incisions 131 are in a multi-lobe shape. The seal 13 may be configured as a circular or duckbill or bullet-shaped valve structure. The sealing member 13 is arranged at a position close to the junction of the main body portion 141 and the constricted portion 142, and of course, it can also be arranged at other positions as required.

When the puncture needle assembly is puncturing, the puncture needle 21 passing through the incision 131 of the sealing member 13 will not cause the incision 131 to open, and the sealing member 13 is still in a closed state at this time, preventing the blood from flowing back out of the outer needle seat 14, blocking the Blood is the transmission route of infectious diseases, thereby reducing the chance of nosocomial infections in patients. During flushing or infusion, after the syringe or infusion tube is connected to the outer needle tube assembly, the fitting on the syringe or infusion tube will push the extrusion member 12 to the sealing member 13, and after the extrusion member 12 cooperates with the boss 111 After the pressing force of the sealant is pressed, it will be deformed to both sides, the middle incision 131 will be opened, the infusion channel 144 will be connected, and effective infusion will be carried out. The opening speed of the sealing member 13 is fast, and the operation is simple and convenient.

In addition, as shown in FIG. 10 , when the sealing member 13 is very thick and the incision cannot be opened by extrusion deformation, the side edge of the sealing member 13 is squeezed by the first bracket 121 and the second bracket 122 and the extrusion direction is shown by the arrow. As shown, a channel 17 is formed between the side edge of the sealing member 13 corresponding to the extrusion position of the arm 121 and the inner wall of the outer needle hub 14, and effective infusion can be performed through the channel 17.

The anti-reflux indwelling needle also includes an indwelling needle sheath 4 and a sheath mounting seat 11 that are connected to each other. As shown in Figures 1 and 2 , the indwelling needle sheath 4 and the sheath mounting seat 11 are sleeved outside the outer needle tube assembly for use in Protect the needle tube 15.

The puncture needle 21 is also sleeved with an anti-stab safety device 3, which is an elastic piece, and can follow the puncture needle 21 to escape from the outer needle seat 14. They are brought out together, and completely cover the tip 21a, so as to avoid the injury caused by the puncture needle 21 to the medical staff and prevent secondary infection.

As shown in FIGS. 8 , 9 and 12 , the stab-proof safety device 3 is an elastic piece, including a bottom blocking piece 31 , a first elastic arm 32 and a second elastic arm 33 connected on both sides of the bottom blocking piece 31 . The first elastic sheet 35 at the front end of the first elastic arm 32 and the second elastic sheet 36 arranged at the front end of the second elastic arm 33 are provided with a through hole 37 for the puncture needle 21 to pass through. A portion of the outer surface of the tip 21a is provided with a limiting protrusion 21b, which can help the puncture needle 21 to be stuck at the through hole 37, so that the puncture needle 21 cannot be separated from the puncture prevention safety device 3 when it is pulled out. And the limiting protrusion 21b is close to the tip 21a of the puncture needle 21 and away from the tail end of the puncture needle 21, and the tail end of the puncture needle 21 is detachably connected to the puncture needle seat 22. In an optional embodiment, the limiting protrusion 21b may be a circle of annular protrusions, or the limiting protrusion 21b may be a plurality of protrusions. The first elastic arm 32 and the second elastic arm 33 are intersected to form an accommodating cavity 34 for accommodating the puncture needle 21 , and the first elastic piece 35 and the second elastic piece 36 are arranged up and down and close to each other at the front end of the closed accommodating cavity 34 . , the structure of the second elastic piece 36 is the same as that of the first elastic piece 35 , and its specific structure is described in detail by taking the first elastic piece 35 as an example. The first elastic piece 35 includes an elbow portion 351 connected with the first elastic arm 32 and bent outward, a wall portion 352 connected with the elbow portion 351 , and an end portion 353 connected with the wall portion 352 and bent. When the puncture needle 21 penetrates the puncture prevention safety device 3, the outer surface of the puncture needle 21 abuts between the end 353 of the first elastic piece 35 and the end 353 of the second elastic piece 36, and the first elastic piece 35 and the second elastic piece 36 is forced to open outward, and the elbow 351 of the first elastic piece 35 and the elbow 351 of the second elastic piece 36 are clamped in the extrusion piece 12, so that the anti-stab safety device 3 is fixed in the extrusion piece 12. . A first blocking piece 39 is provided on both sides of the first elastic piece 35 , and a second blocking piece 38 is provided on both sides of the second elastic piece 36 , and the first blocking piece 39 and the second blocking piece 38 are arranged on the same straight line. When the puncture-proof safety device 3 is initially installed, the tail end of the puncture needle 21 first passes through the first elastic piece 35 and the second elastic piece 36 and then enters the through hole 37 until the part with the limiting protrusion 21b contacts the through hole 37, that is, the puncture. The needle 21 is inserted into the anti-stab wound safety device 3 upside down; when the puncture needle 21 penetrates the anti-stab wound safety device 3, the first elastic piece 35 and the second elastic piece 36 are relatively separated, and under the action of the reset elastic force, the first elastic piece 35 Both the end 353 of the second elastic piece 36 are in contact with the outer surface of the puncture needle 21, and the first elastic arm 32 and the second elastic arm 33 undergo relative displacement and are deformed, causing the through hole 37 to begin to shrink, so as to have a limit protrusion. The puncture needle 21 in part 21b cannot pass through the through hole 37, but the tip 21a of the puncture needle 21 is exposed outside the first elastic piece 35 and the second elastic piece 36. At this time, the puncture prevention safety device 3 has been installed on the puncture needle 21 in place. When the puncture needle 21 is pulled out after the puncture of the human body, the limiting protrusion 21b retreats to the through hole 37 and is blocked and cannot continue to pass through the through hole 37. Therefore, the puncture prevention safety device 3 is pulled out together with the puncture needle 21, and its tip 21a is withdrawn. into the first elastic piece 35 and covered by the curved end 353 and the first blocking piece 39, or its tip 21a retreats into the second elastic piece 36 and is covered by the curved end 353 and the second blocking piece 38. The retraction of the needle tip portion to the first elastic piece 35 or the second elastic piece 36 is determined by the distance between the tip 21a and the limiting protrusion 21b.

It should be pointed out that the above-mentioned preferred embodiment is only to illustrate the technical concept and characteristics of the present utility model, and its purpose is to enable those who are familiar with this technology to understand the content of the present utility model and implement accordingly, and cannot limit the present utility model with this. The scope of protection of the utility model. All equivalent changes or modifications made according to the spirit of the present invention shall be included within the protection scope of the present invention.

Claims

A backflow prevention indwelling needle, comprising a puncture needle (21), an infusion channel (144) defined by an outer needle seat (14), and a valve assembly for sealing the infusion channel (144), characterized in that: the valve The assembly includes a seal (13) and a switch assembly for opening the seal (13), the seal (13) is in a normally closed state to close the infusion channel (144); the switch assembly includes a fixed arrangement A stopper and a movably arranged extrusion (12), the extrusion (12) includes a first part (121a) and a second part (121b) that are connected to each other, and the extrusion (12) has a When the first part (121a) receives an external force and moves toward the sealing member (13), the second part (121b) abuts against the sealing member (13) so that the sealing member (13) is elastic at the stopper Deformation to conduct the infusion channel (144), the external force comes from the force generated when the indwelling needle is matched with the infusion device; when the puncture needle (21) passes through the seal (13), the infusion Channel (144) is not turned on.
The anti-reverse flow indwelling needle according to claim 1, characterized in that: the sealing member (13) has a normally closed cutout, and when the sealing member (13) is elastically deformed, the cutout is opened to allow fluid to pass through.
The anti-reverse flow indwelling needle according to claim 1 or 2, characterized in that: the sealing member (13) is circular, duckbill or bullet-shaped, and the sealing member (13) has elasticity and is elastically squeezed The inner wall of the outer needle seat (14).
The anti-reflux indwelling needle according to claim 1 or 2, characterized in that: the extrusion part (12) and the stopper are both located in the infusion channel (144), and the extrusion part (12) ) and the stoppers are distributed on both sides of the seal (13), and the stoppers are used to prevent the axial movement of the seal (13). A part is away from the seal (13) to cooperate with the infusion device, and a second part of the extrusion (12) is close to the seal (13).
The anti-reflux indwelling needle according to claim 1, characterized in that: the extrusion piece (12) comprises a connecting piece (123) and a plurality of axially extending arms (121), and the connecting piece (123) has The through hole (124) through which the puncture needle (21) is passed is accommodated, and the arm (121) includes the first portion (121a) remote from the seal (13) and a portion close to the seal (13). In the second part (121b), a plurality of the arms (121) are arranged on the outer side of the connecting piece (123), so that the arms (121) are close to the inner wall of the outer needle hub (14).
The anti-backflow indwelling needle according to claim 1, 2 or 4, characterized in that: the stopper comprises a boss (111) fixedly arranged on the inner wall of the outer needle seat (14), the boss (111) 111) Form a barrier to the edge of the seal (13).
The anti-reverse flow indwelling needle according to claim 6, characterized in that: the bosses (111) are provided with two, and the two are axially symmetrical.
The anti-backflow indwelling needle according to claim 1, characterized in that a channel (17) is formed between the side edge of the sealing member (13) after being squeezed and the inner wall of the outer needle seat (14).
The anti-reflux indwelling needle according to claim 1 or 2, characterized in that: the puncture needle (21) is provided with an anti-stab safety device (3), and the anti-stab safety device (3) is used for The tip of the puncture needle (21) is covered when the puncture needle (21) is withdrawn from the infusion channel (144).
The anti-reverse flow indwelling needle according to claim 1, characterized in that: the anti-stab safety device (3) comprises a bottom blocking piece (31), a first elastic piece connected to both sides of the bottom blocking piece (31) The arm (32) and the second elastic arm (33), the first elastic piece (35) arranged at the front end of the first elastic arm (32), and the second elastic piece (35) arranged at the front end of the second elastic arm (33) 36), a through hole (37) for the puncture needle (21) to pass through is opened on the bottom baffle (31), and a part of the outer wall of the puncture needle (21) is provided with a limiting protrusion (21b) .