CN216169202U - Venous indwelling needle - Google Patents

Abstract

The utility model relates to a venous indwelling needle which comprises a cannula base, wherein one end of the cannula base is provided with a cannula, the other end of the cannula base is provided with a control switch, the outer side of the cannula is provided with an extrusion type expansion cavity, the control switch is connected with the extrusion type expansion cavity, and the control switch is used for controlling the contraction or expansion of the extrusion type expansion cavity. Compared with the prior art, the utility model has the beneficial effects that: only need can ensure to form the laminating or non-laminating state that has good toughness between the extrusion formula inflation chamber that sets up and the vascular wall through control switch, and then ensure to be located extrusion formula inflation chamber center and effectively eliminate the sleeve pipe at the intravascular needle phenomenon of running all the time at infusion treatment in-process sleeve pipe, reduce the risk that the sleeve pipe punctures the blood vessel at infusion in-process by a wide margin.

Description

Venous indwelling needle

Technical Field

The utility model relates to the technical field of medical instruments, in particular to a venous indwelling needle.

Background

The vein indwelling needle is also called vein trocar, the core component of the vein indwelling needle comprises a soft catheter or a sleeve which can be indwelling in the blood vessel and a stainless puncture guiding needle core, when in use, the catheter and the needle core can be punctured into the blood vessel together, when the catheter completely enters the blood vessel, the needle core is withdrawn, and only the soft catheter is indwelling in the blood vessel for transfusion treatment. The soft catheter can ensure that the indwelling needle is continuously used for three to five days, and the soft cannula is not easy to have the needle running phenomenon even if a user slightly moves. However, in the process of carrying out infusion treatment on pets, pets usually have scratching on the puncture site of intravenous infusion besides anesthesia, needle running is easy to occur on disposable intravenous infusion needles and intravenous trocars, local tissue edema or swelling pain is easy to occur after needle running, and local tissue inflammation can be caused especially when fluid seepage or strong drug irritation occurs. In addition, the pet body can generate painful reaction, even barking and emotional agitation and the like after the needle running, and normal infusion treatment is easily influenced because the needle running cannot be processed in time under the condition that human beings cannot understand the barking or the body reaction of the pet. At this time, pet hospitals usually choose to keep pets quiet during transfusion through tranquilizer or hypnotic, but repeated administration of the medicine causes harm to the health of the pets.

The existing thyroid cyst suction device utilizes an inflatable expansion air bag, namely an expansion air bag arranged on the outer surface of a remaining soft needle, so that the remaining soft needle can be fixed in a sac cavity, and the technical effects of difficult falling off, convenient operation and pain relief of a patient when effusion is sucked or medicine is injected can be realized. However, the inflatable expansion air bag is easy to be damaged in the inflation process, and the hose is easy to be damaged after puncture, so that the conditions of incapability of inflating or air leakage and the like are caused, and the normal treatment processes of sucking effusion or injecting medicines and the like are influenced. Thus, improvements are still needed.

The existing needle point displacement prevention puncture indwelling needle for vascular malformation sclerosis treatment utilizes a liquid-filled elastic bag, namely, the volume of the elastic bag is expanded after the elastic bag is filled with liquid, so that the end part of a puncture tube is effectively prevented from being separated from a diseased vascular malformation lacuna, and the beneficial effect of quickly ensuring the position stability of a needle head is realized. However, the liquid-filled elastic bag is not only complex in structure, but also needs to be added with a liquid-pumping operation procedure when the remaining needle is pulled out. Thus, improvements are still needed.

SUMMERY OF THE UTILITY MODEL

The utility model provides a venous indwelling needle, which aims to solve the needle running phenomenon caused by scratching of an infusion puncture part when a pet conducts venous infusion and effectively avoid local tissue edema, pain and inflammation caused by the needle running phenomenon.

Compared with the existing indwelling needle comprising an inflatable expansion air bag or a liquid-filled elastic bag and the like, the utility model has the advantages that the structure of the technical scheme is more optimized and simple, and the operation and the use are more convenient and safer by arranging the extrusion type expansion cavity and controlling the opening or the tightening of the extrusion type expansion cavity by the control switch. Particularly, the extrusion type expansion cavity arranged at the position of the indwelling needle sleeve can be effectively controlled through the control switch, so that a fitting or non-fitting state with good toughness is formed between the extrusion type expansion cavity and the vascular wall, the sleeve is always positioned in the center of the extrusion type expansion cavity in the infusion treatment process, the needle running phenomenon of the sleeve in the blood vessel is effectively eliminated, and the risk that the sleeve punctures the blood vessel can be greatly reduced even if a pet scratches the needle head.

Further, the front inner side of the extrusion type expansion cavity is connected with the front outer side of the sleeve, and the extrusion type expansion cavity is identical to the sleeve in length along the axial length of the sleeve in the contraction state, so that the toughness and hardness of the wall of the sleeve cannot be influenced no matter the extrusion type expansion cavity is in the contraction state or in the expansion state.

Further, the extrusion formula inflation chamber adopts netted inflation chamber, netted inflation chamber is anterior including netted chamber, netted chamber middle part and netted chamber rear portion, netted inflation chamber adopts netted wire skeleton, netted wire skeleton includes a plurality of netted wire constitutional units, wherein, the wire diameter of the netted wire constitutional unit at netted chamber middle part is greater than the wire diameter of the netted wire constitutional unit at netted chamber front portion and netted chamber rear portion, the wire surface of the netted wire constitutional unit at netted chamber front portion and the wire surface of the netted wire constitutional unit at netted chamber rear portion all have the cladding of polyurethane, be connected through polyurethane between the anterior inboard in netted chamber and the anterior outside of sleeve pipe, netted chamber rear portion is connected with control switch.

The mesh-shaped metal wire framework with the polyurethane coating on the front part and the rear part of the mesh-shaped cavity is adopted, so that the comfort degree of the mesh-shaped expansion cavity in the blood vessel can be ensured.

And a plurality of reticular metal wire structural units extending out of the rear part of the reticular cavity are wound to form a strand of metal wire, and the strand of metal wire is connected with the control switch.

Furthermore, the front part and the rear part of the reticular cavity both adopt metal wires with the diameter of 1-2.5 microns, the middle part of the reticular cavity adopts metal wires with the diameter of 3-8 microns, and the thickness of the joint of the inner side of the front part of the reticular cavity and the outer side of the front part of the sleeve is 10-50 nanometers.

By adopting the reticular metal wire structural unit with thick two ends and thin middle, the utility model can ensure the comfort of the reticular expansion cavity in the blood vessel, and simultaneously can reduce the using amount of the metal wire, thereby further reducing the manufacturing cost.

Further, the extrusion type expansion cavity can also preferably adopt a film-shaped expansion cavity, the film-shaped expansion cavity comprises a film-shaped cavity front part, a film-shaped cavity middle part and a film-shaped cavity rear part, the film-shaped expansion cavity adopts a structural form that a strip-shaped metal wire interlayer is arranged between two layers of polyurethane films, the inner side of the film-shaped cavity front part is connected with the outer side of the sleeve front part through polyurethane, and the film-shaped cavity rear part is connected with the control switch.

Because the membranous expansion cavity is of a closed structure, in order to ensure that the blood flow in the blood vessel is smooth after the membranous expansion cavity is opened, a certain gap is left between the opened membranous expansion cavity and the inner wall of the blood vessel.

Furthermore, the whole sac cavity of the membrane-shaped expansion cavity is made of polyurethane, strip-shaped metal wires are uniformly distributed in a strip shape between two layers of polyurethane films along the circumferential direction around the sleeve, strip-shaped metal wire bending parts are arranged at the front part and the rear part of the membrane-shaped cavity, the thickness of the membrane-shaped expansion cavity is 0.015-0.03 mm, the diameter of each strip-shaped metal wire is 1-2.5 microns, the thickness of the joint of the front part of the membrane-shaped cavity and the front part of the sleeve is 10-50 nanometers, and the joint is arranged into a connecting structure with relatively small thickness, so that the pain degree of the venous indwelling needle can be guaranteed to be small when the venous indwelling needle is used for puncturing a vein.

Because whole bag chamber is a enclosed construction, the blood flow in the blood vessel is unobstructed after opening for guaranteeing this whole bag chamber, consequently after opening whole bag chamber can not directly laminate on the vascular wall, but need leave certain clearance. In addition, since the diameter of the vein of the pet varies with the body type, the size of the whole sac cavity needs to be determined according to the difference of the diameters of the vein of the pet with large, medium and small body types.

Furthermore, the control switch preferably adopts a push-pull type locking switch, the push-pull type locking switch comprises a switch box, a first guide rail is arranged in the switch box, a guide rail rod is arranged on the first guide rail, a switch button is arranged at one end of the guide rail rod, and the other end of the guide rail rod is connected with the rear part of the reticular expansion cavity.

The operating principle of push-pull type locking switch is similar to that of push type ball-point pen, the guide rail rod is arranged in the initial position clamping groove, when the switch button is pressed and the guide rail rod is pushed, the guide rail rod slides along the first guide rail and moves to the expansion position from the movement track position, the extrusion type expansion cavity is gradually changed into the expansion state from the contraction state, when the switch button is pressed again, the guide rail rod sequentially passes through the recovery position, the turning position and the turning position along the first guide rail and then returns to the initial position, and at the moment, the extrusion type expansion cavity is gradually changed into the contraction state from the expansion state.

Further, the control switch can also preferably adopt a press type automatic telescopic locking switch, the press type automatic telescopic locking switch comprises a switch box, a second guide rail is arranged in the switch box, a sliding claw sleeve and a push rod are sequentially sleeved on the second guide rail, a guide groove is formed in the side wall of the sliding claw sleeve, the lower portion of the sliding claw sleeve is connected with the extrusion type expansion cavity and is sleeved with a locking spring, a press spring is sleeved on the outer wall of the push rod, and a switch button is arranged at the top end of the push rod.

The working principle of the pressing type automatic telescopic locking switch is similar to that of a pressing type ball-point pen, firstly, a switch button is pressed to enable a push rod to push a sliding claw sleeve to move from an initial position to a critical point position at the bottom of a second guide rail; secondly, under the pushing of a locking spring, the sliding claw sleeve rotates towards the right side along the trend; thirdly, the push rod rebounds upwards under the action of the pressing spring, and after the push rod passes through a critical point, the sliding claw sleeve continues to rotate towards the right side and is clamped at the second guide rail; and finally, the push rod continuously rebounds to the initial position, and the extrusion type expansion cavity is gradually changed from the contraction state to the expansion state. When the switch button is pressed again, the extrusion type expansion cavity can be gradually changed from the expansion state to the contraction state by repeating the steps.

Furthermore, the reticular metal wire structural unit and the strip-shaped metal wires are made of stainless steel, the stainless steel can be preferably made of nickel-titanium alloy or cobalt-chromium alloy, and the nickel-titanium alloy or the cobalt-chromium alloy has good performance and small influence on blood vessels.

Furthermore, the device also comprises a needle seat, and the control switch is connected with the needle seat at one end far away from the cannula seat.

Furthermore, a needle head is arranged in the needle seat, so that the function of indwelling needle infusion is realized.

Furthermore, a needle head protective sleeve is arranged on the outer wall of the sleeve seat, a catheter extension arm is arranged on the outer wall of the needle head protective sleeve, an extension tube is arranged at one end, away from the pillow protective sleeve, of the catheter extension arm, and a heparin cap is arranged at one end, away from the catheter extension arm, of the extension tube. The heparin cap can be matched with an arteriovenous indwelling needle for use, can be punctured for multiple times and repeatedly for transfusion and medicine injection, is provided with a standard locking joint, the catheter extension arm, the extension tube and the heparin cap can be matched for use, and can prevent blood backflow and anticoagulation by injecting heparin sodium.

Furthermore, the extension tube is sleeved with a tube sealing clamp, and the tube sealing clamp is used for sealing or communicating the extension tube according to the infusion requirement.

Furthermore, the needle wing is arranged on the needle base, so that the indwelling needle can be conveniently held by hand to carry out intravenous injection operation.

Furthermore, the needle seat is externally fixed by adopting a reticular elastic bandage, so that the retention time of the venous retention needle in the venous blood vessel of the pet can be further prolonged, and the occurrence of vasculitis and other conditions can be effectively reduced.

Drawings

FIG. 1 is a schematic structural diagram of a preferred embodiment of the present invention;

FIG. 2 is a schematic view of the preferred embodiment of the present invention in a contracted state when a mesh-like expansion chamber is used;

FIG. 3 is a schematic view of the expanded state of a preferred embodiment of the present invention when a mesh-like expansion chamber is used;

FIG. 4 is a schematic diagram of the shape of a preferred embodiment of the utility model in both its contracted and expanded states and its structural elements of the mesh wire;

FIG. 5 is a schematic view of the front portion of a reticulated cavity when a reticulated expansion cavity is used in a preferred embodiment of the present invention;

FIG. 6 is a schematic diagram of the structure and operation principle of a push-pull type locking switch according to a preferred embodiment of the present invention;

FIG. 7 is a schematic view of the mesh-like expansion chamber in a contracted state before the needle is not removed in accordance with a preferred embodiment of the present invention;

FIG. 8 is a schematic view of the expanded state of the mesh-like expansion chamber before the needle is removed in accordance with a preferred embodiment of the present invention;

FIG. 9 is a schematic view of the expanded state of the mesh-like expansion chamber after the needle has been withdrawn in accordance with a preferred embodiment of the present invention;

FIG. 10 is a schematic view of the external configuration of a preferred embodiment of the present invention using a membranous inflation lumen;

fig. 11 is a schematic view of a sandwich arrangement of strip-shaped wires using a membranous inflation lumen in another preferred embodiment of the utility model.

Description of reference numerals:

1, a needle head; 2 a mesh-shaped expansion cavity; 3, sleeving a sleeve; 4, a sleeve seat; 5, needle head protective sleeve; 6 a catheter extension arm; 7 needle wings; 8, a needle seat; 9, sealing the pipe clamp; 10 an extension tube; 11 a heparin cap; 12 a switch button; 13 a control switch; 14 a mesh wire framework; 15 mesh wire structural units; 16 polyurethane; 17 a front part of the reticular cavity; 18 mesh cavity middle; 19 rear part of the reticular cavity; 20 a switch box; 21 a first guide rail; 22 a guide rail rod; 23 a membranous inflation lumen; the front of the 24 membranous cavity; 25 middle part of the membranous cavity; 26 the rear of the membranous cavity; 27 a polyurethane film; 28 strip wires.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

In the description of the present invention, it should be noted that terms such as "upper", "lower", "front", "rear", "left", "right", and the like in the embodiments indicate terms of orientation, and are used only for simplifying the description of positional relationships based on the drawings of the specification, and do not represent that elements, devices, and the like that are referred to must operate according to specific orientations and defined operations and methods, configurations in the specification, and such terms of orientation do not constitute limitations of the present invention.

In the description of embodiments of the present application, the description of the term "some embodiments" means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

In order to solve the problem of needle running caused by scratching of a transfusion puncture part during venous transfusion of a pet, effectively avoid local tissue edema, pain and inflammation caused by the phenomenon, and solve the technical problems that an existing thyroid cyst suction device cannot be inflated due to the fact that an inflatable expansion air bag is easy to damage, and an existing needle point displacement prevention puncture indwelling needle is complex in structure and complex in operation due to a liquid-filled elastic bag, the utility model provides a venous indwelling needle with an extrusion type expansion cavity, and the preferred embodiment of the venous indwelling needle is as follows: as shown in fig. 1 to 9, a venous indwelling needle comprises a cannula holder 4, a cannula 3 is arranged at one end of the cannula holder 4, a control switch 13 is arranged at the other end of the cannula holder, an extrusion type expansion cavity is arranged at the outer side of the cannula 3, the control switch 13 is connected with the extrusion type expansion cavity, and the control switch 13 is used for controlling the contraction or expansion of the extrusion type expansion cavity.

Compared with the existing indwelling needle comprising an inflatable expansion air bag or a liquid-filled elastic bag and the like, the embodiment has the advantages that the structure is optimized and simple, and the operation and the use are more convenient and safe by arranging the extrusion type expansion cavity and controlling the opening or the tightening of the extrusion type expansion cavity by the control switch 13. Particularly, this embodiment can effective control keep somewhere the extrusion formula inflation chamber that needle sleeve pipe 3 department set up through control switch 13, make and form the laminating or non-laminating state that has good toughness between it and the vascular wall to ensure in the infusion treatment process, sleeve pipe 3 is located extrusion formula inflation chamber center all the time, and effectively eliminate sleeve pipe 3 at the intraductal needle phenomenon of running of blood, even when the pet scratches syringe needle department, also can reduce sleeve pipe 3 puncture vascular risk by a wide margin.

Specifically, the anterior inboard in extrusion formula expansion chamber is connected with the anterior outside of sleeve pipe 3, and extrusion formula expansion chamber is the same with sleeve pipe 3 length along 3 axial length of sleeve pipe when the contraction state, therefore no matter extrusion formula expansion chamber is in the contraction state or when expanding state, it can not cause any influence to 3 pipe wall toughness of sleeve pipe and hardness.

Specifically, the extrusion type expansion cavity adopts a netted expansion cavity 2, the netted expansion cavity 2 comprises a netted cavity front part 17, a netted cavity middle part 18 and a netted cavity rear part 19, the netted expansion cavity 2 adopts a netted metal wire framework 14, the netted metal wire framework 14 comprises a plurality of netted metal wire structural units 15, wherein the metal wire diameter of the netted metal wire structural unit 15 in the netted cavity middle part 18 is larger than the metal wire diameter of the netted metal wire structural unit 15 in the netted cavity front part 17 and the netted cavity rear part 19, the metal wire outer surfaces of the netted metal wire structural units 15 in the netted cavity front part 17 and the metal wire outer surfaces of the netted metal wire structural units 15 in the netted cavity rear part 19 are both coated with polyurethane 16, the inner side of the netted cavity front part 17 is connected with the outer side of the sleeve 3 front part through the polyurethane 16, and the netted cavity rear part 19 is connected with the control switch 13.

In the embodiment, the comfort of the reticular expansion cavity 2 in the blood vessel can be ensured by adopting the reticular metal wire framework 14 which is coated with the polyurethane 16 at the front part and the rear part of the reticular cavity.

A plurality of net-shaped wire structural units 15 extending from the rear part 19 of the net-shaped cavity are wound to form a strand of wire, and the strand of wire is connected with the control switch 13.

The front part 17 and the rear part 19 of the reticular cavity both adopt metal wires with the diameter of 1-2.5 microns, the middle part 18 of the reticular cavity adopts metal wires with the diameter of 3-8 microns, and the thickness of the joint between the inner side of the front part 17 of the reticular cavity and the outer side of the front part of the sleeve 3 is 10-50 nanometers.

This embodiment can guarantee the comfort level of netted inflation chamber 2 in vascular inside through adopting both ends thick middle thin netted wire constitutional unit 15, can also reduce the wire quantity simultaneously, further reduces manufacturing cost.

The mesh-shaped wire structural unit 15 is preferably made of stainless steel, and the stainless steel can be preferably made of nickel-titanium alloy or cobalt-chromium alloy, and the nickel-titanium alloy or the cobalt-chromium alloy has good performance and small influence on blood vessels.

Specifically, the control switch 13 is a push-pull type locking switch, which includes a switch box 20, a first guide rail 21 is arranged in the switch box 20, a guide rail rod 22 is mounted on the first guide rail 21, one end of the guide rail rod 22 is provided with the switch button 12, and the other end is connected with the rear portion 19 of the reticular cavity.

The operating principle of the push-pull type locking switch is similar to that of a push type ball pen, the guide rail rod 22 is arranged in the initial position clamping groove, when the switch button 12 is pressed and the guide rail rod 22 is pushed, the guide rail rod 22 slides along the first guide rail 21 and moves to the expansion position from the movement track position, the extrusion type expansion cavity is gradually changed into the expansion state from the contraction state at the moment, when the switch button 12 is pressed again, the guide rail rod 22 sequentially passes through the first guide rail 21 to return to the initial position, the turning position and the turning position, and the extrusion type expansion cavity is gradually changed into the contraction state from the expansion state at the moment.

In particular, a needle seat 8 is further included, and a control switch 13 is connected with the needle seat 8 at one end far away from the cannula seat 4. The needle head 1 is arranged in the needle seat 8 to realize the function of remaining needle transfusion. The outer wall of the cannula seat 4 is provided with a needle head protecting sleeve 5, the outer wall of the needle head protecting sleeve 5 is provided with a catheter extending arm 6, the catheter extending arm 6 is provided with an extending pipe 10 at one end far away from the needle head protecting sleeve 5, and the extending pipe 10 is provided with a heparin cap 11 at one end far away from the catheter extending arm 6. Wherein, the heparin cap 11 can be used with the arteriovenous indwelling needle, can puncture for a plurality of times and repeatedly for transfusion and injection of medicine, and is provided with a standard locking joint, the catheter extension arm 6, the extension tube 10 and the heparin cap 11 can be used in a matching way, and the blood backflow and anticoagulation can be prevented by injecting heparin sodium.

Specifically, the extension tube 10 is sleeved with a tube sealing clamp 9, and the tube sealing clamp 9 is used for sealing or communicating the extension tube 10 according to the transfusion requirement. The needle seat 8 is provided with a needle wing 7, which is convenient for holding the remaining needle by hand to carry out intravenous injection operation. The needle seat 8 is externally fixed by a reticular elastic bandage, so that the retention time of the venous indwelling needle in the venous blood vessel of the pet can be further prolonged, and the occurrence of vasculitis and other conditions can be effectively reduced.

This embodiment is through preferred plug-type locking switch, can realize the laminating state of good toughness between netted inflation chamber 2 and the vascular wall equally to ensure that sleeve pipe 3 in the infusion is located netted inflation chamber 2 center all the time, and effectively eliminate the run needle phenomenon, reduce the risk that sleeve pipe 3 punctures the blood vessel by a wide margin. During the concrete operation, can pierce in pet forearm vein blood vessel and open push-pull type locking switch after the intraductal blood return that appears, open netted inflation chamber 2 back through the extrusion force, sleeve pipe 3 is located netted inflation chamber 2 central authorities all the time to laminate completely at the vein inner wall, can withdraw from built-in syringe needle 1 afterwards, reuse netted elastic bandage winding shank and needle file 8 department can.

Exemplarily, the workflow of this embodiment is specifically as follows:

1) after the rubber band is tied at the front leg of the pet, standing for a moment and waiting for the vein to expand;

2) the forearm of the pet is held up by a hand to observe the blood vessel, the skin at the ligation part is slightly pressed by fingers, and the part which is obviously raised, has better elasticity and slides is a vein;

3) the optimal intravenous injection site is 3 centimeters above and slightly inward of the first joint of the front leg of the pet;

4) air in the indwelling needle tube is emptied until liquid flows out of the needle head 1;

5) holding the front leg of the pet by the left hand, and fixing the skin of the vein by the fingers;

6) holding the remaining needle with the right hand to enable the needle head to be at an angle of 90 degrees or 45 degrees with the skin, and pushing the needle head 1 into the vein after blood return is observed;

7) the switch button 12 is turned on, the blood vessel is lightly pressed by fingers, and when the blood vessel is sensed to be enlarged and hard, the reticular inflation cavity 2 is completely opened;

8) pushing out the built-in needle head 1;

9) fixing the needle head 1 by using an elastic net bandage;

10) taking down the rubber band, opening the drip and adjusting the drip to normal speed;

11) when the drip is finished, the switch button 12 is pressed again, the blood vessel is lightly touched by the fingers, when the blood vessel is sensed to be shrunk and soft, the reticular inflation cavity 2 is indicated to be completely shrunk, and then the sleeve 3 is pressed and pulled out by a cotton ball.

In this embodiment, as shown in fig. 10 and 11, the extrusion type expansion chamber may also preferably adopt a film-shaped expansion chamber 23, the film-shaped expansion chamber 23 comprises a film-shaped chamber front part 24, a film-shaped chamber middle part 25 and a film-shaped chamber rear part 26, the film-shaped expansion chamber 23 is in a structural form that a strip-shaped metal wire 28 is arranged between two layers of polyurethane films 27, the inner side of the film-shaped chamber front part 24 is connected with the outer side of the front part of the sleeve 3 through the polyurethane 16, and the film-shaped chamber rear part 26 is connected with the control switch 13.

Because the membranous expansion cavity 23 is a closed structure, in order to ensure that the blood flow in the blood vessel is smooth after the membranous expansion cavity 23 is opened, a certain gap is left between the opened membranous expansion cavity 23 and the inner wall of the blood vessel.

Specifically, the integral sac cavity of the film-shaped expansion cavity 23 is made of polyurethane 16, strip-shaped metal wires 28 are arranged between two layers of polyurethane films 27 and are uniformly distributed in a strip shape along the circumferential direction around the sleeve 3, the bending parts of the strip-shaped metal wires 28 are arranged at the front part 24 and the rear part 26 of the film-shaped cavity, the thickness of the film-shaped expansion cavity 23 is 0.015-0.03 mm, the diameter of the strip-shaped metal wires 28 is 1-2.5 microns, the thickness of the connecting part between the front part 24 of the film-shaped cavity and the front part of the sleeve 3 is 10-50 nanometers, and the connecting structure with relatively small thickness at the connecting part can ensure that the pain degree of the venous indwelling needle for veins is small when the venous indwelling needle is used for puncturing veins. Because whole bag chamber is a enclosed construction, the blood flow in the blood vessel is unobstructed after opening for guaranteeing this whole bag chamber, consequently the whole bag chamber after opening can not directly laminate on the vascular wall, but need leave certain clearance. In addition, since the diameter of the vein of the pet varies with the body type, the size of the whole sac cavity needs to be determined according to the difference of the diameters of the vein of the pet with large, medium and small body types.

Specifically, the strip-shaped metal wire 28 is made of stainless steel, and the stainless steel may preferably be nickel-titanium alloy or cobalt-chromium alloy, which not only has good performance but also has small influence on blood vessels.

When the film-shaped expansion chamber 23 is preferably used, after the switch button 12 is pressed, the strip-shaped metal wires 28 at the rear part 26 of the film-shaped chamber are unfolded outwards under the pushing force of the guide rail rod 22 in the push-pull type locking switch, the whole capsule chamber is opened under the pushing and pressing of the strip-shaped metal wires 28 at the rear part 26 of the film-shaped chamber, and the strip-shaped metal wires 28 squeezing the front part 24 of the film-shaped chamber are further pushed and unfolded outwards. The preferable scheme can also realize a non-attaching state with good toughness between the membranous expansion cavity 23 and the vessel wall, thereby ensuring that the cannula 3 is always positioned at the center of the membranous expansion cavity 23 in the transfusion, effectively eliminating the needle running phenomenon of the cannula 3 and greatly reducing the risk of puncturing the vessel by the cannula 3.

In this embodiment, the control switch 13 may also preferably adopt a push-type automatic retractable locking switch, the push-type automatic retractable locking switch includes a switch box 20, a second guide rail is installed in the switch box 20, a sliding claw sleeve and a push rod are sequentially sleeved on the second guide rail, a guide groove is formed on a side wall of the sliding claw sleeve, a lower portion of the sliding claw sleeve is connected with the extrusion type expansion cavity and is sleeved with a locking spring, a push spring is sleeved on an outer wall of the push rod, and a switch button 12 is installed at a top end of the push rod.

The working principle of the pressing type automatic telescopic locking switch is similar to that of a pressing type ball-point pen, firstly, a switch button 12 is pressed to enable a push rod to push a sliding claw sleeve to move from an initial position to a critical point position at the bottom of a second guide rail; secondly, under the pushing of a locking spring, the sliding claw sleeve rotates towards the right side along the trend; thirdly, the push rod rebounds upwards under the action of the pressing spring, and after the push rod passes through a critical point, the sliding claw sleeve continues to rotate towards the right side and is clamped at the second guide rail; and finally, the push rod continuously rebounds to the initial position, and the extrusion type expansion cavity is gradually changed from the contraction state to the expansion state. When the switch button 12 is pressed again, the extrusion type expansion cavity can be gradually changed from the expansion state to the contraction state by repeating the steps.

It can be seen that, when the automatic flexible locking switch of preferred adoption push type, can guarantee equally that extrusion formula inflation chamber and vascular wall between form the laminating or the non-laminating state that has good toughness to ensure that sleeve pipe 3 is located extrusion formula inflation chamber center all the time in the infusion, and effectively eliminate sleeve pipe 3's run needle phenomenon, reduce the vascular risk of sleeve pipe 3 puncture by a wide margin.

Although the present disclosure discloses the above technical solutions, the scope of the present disclosure is not limited thereto. Those skilled in the art can make various changes and modifications to the above-described technical solution without departing from the spirit and scope of the present disclosure, and such changes and modifications will fall within the scope of the present disclosure.

Claims (10)

1. The utility model provides a needle is kept somewhere to vein, its characterized in that includes cannula holder (4), and cannula (3) are equipped with to cannula holder (4) one end, and control switch (13) are equipped with to the other end, and the cannula (3) outside is provided with extrusion formula expansion chamber, and control switch (13) are connected with extrusion formula expansion chamber, and control switch (13) are used for controlling extrusion formula expansion chamber's shrink or inflation.

2. The venous indwelling needle according to claim 1, wherein the extrusion type expansion chamber is a mesh-type expansion chamber (2), the mesh-type expansion chamber (2) comprises a mesh-type chamber front part (17), a mesh-type chamber middle part (18) and a mesh-type chamber rear part (19), the mesh-type expansion chamber (2) is a mesh-type metal wire framework (14), the mesh-type metal wire framework (14) comprises a plurality of mesh-type metal wire structural units (15), wherein the metal wire diameter of the mesh-type metal wire structural unit (15) in the mesh-type chamber middle part (18) is larger than that of the mesh-type metal wire structural units (15) in the mesh-type chamber front part (17) and the mesh-type chamber rear part (19), the metal wire surfaces of the mesh-type metal wire structural units (15) in the mesh-type chamber front part (17) and those of the mesh-type metal wire structural units (15) in the mesh-type chamber rear part (19) are coated with polyurethane (16), the inner side of the front part (17) of the reticular cavity is connected with the outer side of the front part of the sleeve (3) through polyurethane (16), and the rear part (19) of the reticular cavity is connected with a control switch (13).

3. The venous indwelling needle of claim 2, wherein the mesh cavity anterior portion (17) and the mesh cavity posterior portion (19) are both made of wires with a diameter of 1-2.5 microns, the mesh cavity middle portion (18) is made of wires with a diameter of 3-8 microns, and the thickness of the junction between the inside of the mesh cavity anterior portion (17) and the outside of the cannula anterior portion (3) is 10-50 nm.

4. The venous indwelling needle according to claim 1, wherein the extrusion type expansion chamber is a film-shaped expansion chamber (23), the film-shaped expansion chamber (23) comprises a film-shaped chamber front part (24), a film-shaped chamber middle part (25) and a film-shaped chamber rear part (26), the film-shaped expansion chamber (23) is in a structural form that a sandwich of a strip-shaped metal wire (28) is arranged between two layers of polyurethane films (27), the film-shaped chamber front part (24) is connected with the front part of the cannula (3) through polyurethane (16), and the film-shaped chamber rear part (26) is connected with the control switch (13).

5. The venous indwelling needle of claim 4, wherein the integral sac of the membranous cavity (23) is made of polyurethane (16), the strip-shaped metal wires (28) are arranged between two layers of polyurethane films (27) and are uniformly distributed in a strip shape along the circumferential direction around the sleeve (3), the front part (24) and the rear part (26) of the membranous cavity are both provided with bending parts of the strip-shaped metal wires (28), the thickness of the membranous cavity (23) is 0.015-0.03 mm, the diameter of the strip-shaped metal wires (28) is 1-2.5 microns, and the thickness of the joint of the front part (24) of the membranous cavity and the front part of the sleeve (3) is 10-50 nanometers.

6. The venous indwelling needle of claim 1, wherein the control switch (13) is a push-pull locking switch comprising a switch case (20), a first guide rail (21) is provided in the switch case (20), a guide rail rod (22) is provided on the first guide rail (21), the switch button (12) is provided on one end of the guide rail rod (22), and the other end is connected to the rear part (19) of the reticular cavity.

7. The venous indwelling needle according to claim 1, wherein the control switch (13) is a push-type automatic retractable locking switch, the push-type automatic retractable locking switch comprises a switch box (20), a second guide rail is arranged in the switch box (20), a sliding claw sleeve and a push rod are sequentially sleeved on the second guide rail, a guide groove is formed in the side wall of the sliding claw sleeve, the lower portion of the sliding claw sleeve is connected with the extrusion type expansion cavity and sleeved with a locking spring, a pressing spring is sleeved on the outer wall of the push rod, and a switch button (12) is arranged at the top end of the push rod.

8. The venous retention needle according to claim 2, characterized in that the reticular metallic wire structural unit (15) is made of stainless steel.

9. The venous retention needle according to claim 4, characterized in that the strip-shaped wire (28) is made of stainless steel.

10. The venous indwelling needle of claim 1, further comprising a hub (8), the control switch (13) being connected to the hub (8) at an end remote from the cannula hub (4).

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