阅读说明：本技术 回液装置和有创压力传感器 (Liquid return device and invasive pressure sensor ) 是由 王五星 于敬军 王德忍 于 2019-10-11 设计创作，主要内容包括：本发明公开一种回液装置和有创压力传感器,其中,该回液装置用于有创压力传感器,所述有创压力传感器包括采血阀和压力测试组件,所述回液装置包括回液筒,所述回液筒形成有容纳腔,所述回液筒的侧壁还设有连通所述容纳腔的进液口和出液口；和活塞,所述活塞包括活塞头和活塞杆,所述活塞头可活动设于所述容纳腔内,所述活塞杆伸入所述容纳腔并与所述活塞头背离所述进液口和所述出液口的表面连接,所述活塞杆相对所述回液筒伸缩,以带动所述活塞头于所述容纳腔内移动,以使压力测试液经由所述出液口流出。本发明技术方案优化有创压力传感器,将通过有创压力传感器采血后管路中的血液送回至人体内,避免血液的浪费。(The invention discloses a liquid returning device and an invasive pressure sensor, wherein the liquid returning device is used for the invasive pressure sensor, the invasive pressure sensor comprises a blood sampling valve and a pressure testing assembly, the liquid returning device comprises a liquid returning cylinder, an accommodating cavity is formed in the liquid returning cylinder, and a liquid inlet and a liquid outlet which are communicated with the accommodating cavity are further formed in the side wall of the liquid returning cylinder; and the piston comprises a piston head and a piston rod, the piston head is movably arranged in the accommodating cavity, the piston rod extends into the accommodating cavity and is deviated from the liquid inlet and the surface of the liquid outlet, the piston rod is relative to the liquid return cylinder and stretches out and draws back to drive the piston head to move in the accommodating cavity so that the pressure test liquid flows out from the liquid outlet. According to the technical scheme, the invasive pressure sensor is optimized, and the blood in the pipeline after the blood is collected by the invasive pressure sensor is sent back to the human body, so that the waste of the blood is avoided.)

1. A fluid return apparatus for an invasive pressure sensor including a blood collection valve and a pressure test assembly, the fluid return apparatus comprising:

the liquid return cylinder is provided with an accommodating cavity, the side wall of the liquid return cylinder is also provided with a liquid inlet and a liquid outlet which are communicated with the accommodating cavity, the liquid inlet is communicated with the pressure testing assembly, and the liquid outlet is communicated with the blood sampling valve; and

the piston comprises a piston head and a piston rod, the piston head is movably arranged in the accommodating cavity, the piston rod extends into the accommodating cavity and is deviated from the liquid inlet and the surface of the liquid outlet, the piston rod stretches relative to the liquid return cylinder to drive the piston head to move in the accommodating cavity, so that the pressure test liquid flows out from the liquid outlet.

2. The fluid return apparatus of claim 1, wherein the fluid return cylinder has a length direction, the piston head extends along the length direction of the fluid return cylinder, the piston rod comprises a main rod body and at least two reinforcing rods, the main rod body is disposed between the at least two reinforcing rods, and the reinforcing rods and the main rod body are disposed along the length direction of the piston head.

3. The fluid returning device of claim 2, wherein the piston rod is further provided with a handle, and the handle is connected with the main rod body.

4. The fluid returning device according to claim 1, wherein the fluid inlet and the fluid outlet are disposed opposite to an end of the fluid returning cylinder away from the piston rod.

5. The liquid returning device according to any one of claims 1 to 4, wherein the liquid returning cylinder comprises a cylinder body and a cover body, the cylinder body is formed with a containing groove, and the liquid inlet and the liquid outlet are arranged away from an opening of the containing groove;

the lid can be dismantled the lid and fit the opening of holding tank, and with the holding tank encloses to close and forms hold the chamber, the lid is equipped with lets a mouthful, the piston rod at least part runs through it stretches out to hold the chamber to let a mouthful.

6. The fluid returning device of claim 5, wherein the barrel is provided with a first position-limiting structure at the opening of the accommodating groove, the inner wall of the cover is provided with a second position-limiting structure, and when the cover is covered on the accommodating groove, the first position-limiting structure and the second position-limiting structure cooperate to limit the cover from separating from the barrel.

7. The liquid returning device of claim 5, further comprising a protective cover, wherein the protective cover comprises a fixing portion, an extending portion and a handheld portion, the fixing portion is fixed on the outer side wall of the cylinder body, and the handheld portion covers the cover body and the end portion of the piston rod away from the piston head.

8. The liquid returning device according to any one of claims 1 to 4, wherein the outer side wall of the liquid returning cylinder is formed with a first connector and a second connector at the liquid inlet and the liquid outlet, the liquid inlet is connected with the pressure testing assembly, and the liquid outlet is connected with the blood sampling valve.

9. The fluid returning device of claim 8, further comprising a fixing base, wherein the fixing base comprises a fixing plate and two fixing buckles protruding from the surface of the fixing plate, the two fixing buckles respectively fix the first connector and the second connector, the fixing plate is provided with a fixing hole, and the fixing plate fixes the fluid returning device through the cooperation of the connecting piece and the fixing hole.

10. An invasive pressure sensor, comprising a blood collection valve, a pressure test assembly, and a fluid return device according to any one of claims 1 to 9, the fluid return device having an inlet in communication with the pressure test assembly and an outlet in communication with the blood collection valve.

Technical Field

The invention relates to the technical field of medical instruments, in particular to a liquid returning device and an invasive pressure sensor with the same.

Background

The medical invasive pressure sensor is an invasive arteriovenous pressure monitoring device, can continuously and dynamically monitor a plurality of pressures of arterial pressure, central venous pressure, pulmonary arterial pressure and left coronary arterial pressure of a human body, directly obtains physiological parameters of blood pressure, and provides objective basis for diagnosis, treatment and prognosis estimation of clinical diseases. The existing invasive pressure sensor is provided with a blood sampling plug, blood of a monitored person can be collected through the blood sampling plug, but after blood sampling is carried out through the blood sampling plug, the blood inside a pipeline cannot be cleaned up, so that blood is remained in the pipeline, the waste of the blood can be caused, and the risk of blood infection can exist.

The above is only for the purpose of assisting understanding of the technical solutions of the present application, and does not represent an admission that the above is prior art.

Disclosure of Invention

The invention mainly aims to provide a liquid return device, aiming at optimizing an invasive pressure sensor, and returning blood in a pipeline after blood is collected by the invasive pressure sensor to the human body so as to avoid waste of the blood.

In order to achieve the above object, the present invention provides a fluid returning device for an invasive pressure sensor, the invasive pressure sensor including a blood sampling valve and a pressure testing assembly, the fluid returning device including:

the liquid return cylinder is provided with an accommodating cavity, the side wall of the liquid return cylinder is also provided with a liquid inlet and a liquid outlet which are communicated with the accommodating cavity, the liquid inlet is communicated with the pressure testing assembly, and the liquid outlet is communicated with the blood sampling valve; and

the piston, the piston includes piston head and piston rod, the piston head is mobile to be located hold the intracavity, the piston rod stretches into hold the chamber and with the piston head deviates from the inlet with the surface connection of liquid outlet, the piston rod is relative return the liquid cylinder is flexible, in order to drive the piston head in hold the intracavity and remove, make pressure test liquid flow out via the liquid outlet.

In an embodiment of the invention, the liquid return cylinder has a length direction, the piston head extends along the length direction of the liquid return cylinder, the piston rod includes a main rod body and two reinforcing rods, the main rod body is disposed between the two reinforcing rods, and the reinforcing rods and the main rod body are disposed along the length direction of the piston head.

In an embodiment of the present invention, the piston rod is further provided with a handle, and the handle is connected with the main rod body.

In an embodiment of the present invention, the liquid inlet and the liquid outlet are oppositely disposed at an end of the liquid return cylinder away from the piston rod.

In an embodiment of the present invention, the liquid return cylinder includes a cylinder body and a cover body, the cylinder body forms an accommodating groove, and the liquid inlet and the liquid outlet are arranged away from an opening of the accommodating groove;

the lid can be dismantled the lid and fit the opening of holding tank, and with the holding tank encloses to close and forms hold the chamber, the lid is equipped with lets a mouthful, the piston rod at least part runs through it stretches out to hold the chamber to let a mouthful.

In an embodiment of the invention, the barrel is provided with a first limiting structure at an opening of the accommodating groove, the inner wall of the cover body is provided with a second limiting structure, and when the cover body covers the accommodating groove, the first limiting structure and the second limiting structure cooperate to limit the cover body from separating from the barrel.

In an embodiment of the invention, the liquid return device further includes a protective cover, the protective cover includes a fixing portion, an extending portion and a handheld portion, the fixing portion, the extending portion and the handheld portion are sequentially connected, the protective cover is sleeved on the liquid return cylinder, the fixing portion is fixed on the outer side wall of the cylinder body, and the handheld portion covers the cover body and the end portion, away from the piston head, of the piston rod.

In an embodiment of the present invention, a first connector and a second connector are formed on the outer side wall of the liquid return cylinder at the liquid inlet and the liquid outlet, the liquid inlet is connected to the pressure testing assembly, and the liquid outlet is connected to the blood sampling valve.

In an embodiment of the invention, the liquid returning device further includes a fixing base, the fixing base includes a fixing plate and two fixing buckles protruding from the surface of the fixing plate, the two fixing buckles respectively clamp and fix the first connector and the second connector, the fixing plate is provided with a fixing hole, and the fixing plate fixes the liquid returning device through the matching of the connecting piece and the fixing hole.

The invention also provides an invasive pressure sensor which comprises a blood sampling valve, a pressure testing assembly and the liquid returning device, wherein a liquid inlet of the liquid returning device is communicated with the pressure testing assembly, and a liquid outlet of the liquid returning device is communicated with the blood sampling valve.

According to the technical scheme, the liquid return cylinder of the liquid return device is provided with the accommodating cavity, the accommodating cavity is used for storing the pressure test liquid, the side wall of the liquid return cylinder is further provided with a liquid inlet and a liquid outlet which are communicated with the accommodating cavity, the accommodating cavity is also movably provided with the piston, and the piston head in the accommodating cavity is controlled to move relative to the accommodating cavity by operating the piston rod so as to suck or extrude the pressure test liquid stored in the accommodating cavity. Before the invasive pressure sensor is used, the pipeline of the pressure sensor needs to be filled with pressure testing liquid, and at the moment, the piston rod is pulled outwards, so that the pressure testing liquid in the pipeline channel can be sucked into the accommodating cavity from the liquid inlet. After the blood sampling operation is completed through the blood sampling valve with the invasive pressure sensor, the piston rod is pushed towards the inner side again, so that the pressure test liquid in the accommodating cavity flows out through the liquid outlet, and at the moment, the pressure test liquid flowing out of the accommodating cavity can send back the blood remained in the catheter between the blood sampling valve and the blood vessel of the monitored person to the monitored person. Blood between blood sampling valve and the monitored person is sent back to inside the blood vessel of monitored person by the pressure test liquid in holding the chamber, avoids the extravagant phenomenon that blood stopped to cause in the pipe, has also avoided blood to remain the risk of being infected in the pipe.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 is a schematic structural diagram of a liquid returning apparatus according to an embodiment of the present invention;

FIG. 2 is an exploded view of the liquid returning device of FIG. 1;

FIG. 3 is a cross-sectional view of the fluid returning apparatus of FIG. 1;

the reference numbers illustrate:

reference numerals	Name (R)	Reference numerals	Name (R)
				100	Liquid return device	33	Piston rod
10	Liquid return cylinder	331	Main rod body
				11	Barrel body	333	Reinforcing bar
111	Containing cavity	35	Sealing rubber plug
				112	First limit structure	37	Handle (CN)
113	Liquid inlet	50	Protective cover
				115	Liquid outlet	51	Hand-held part
117	First connector	53	Extension part
				119	Second connector	55	Fixing part
13	Cover body	17	Fixed seat
				131	Let a mouthful	171	Fixing plate
133	Second limit structure	173	Fixing hole
				30	Piston	175	Fixing buckle
31	Piston head

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that all the directional indicators (such as up, down, left, right, front, and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the movement situation, etc. in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indicator is changed accordingly.

In the present invention, unless otherwise expressly stated or limited, the terms "connected," "secured," and the like are to be construed broadly, and for example, "secured" may be a fixed connection, a removable connection, or an integral part; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In addition, the descriptions related to "first", "second", etc. in the present invention are only for descriptive purposes and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, the meaning of "and/or" appearing throughout is to include three juxtapositions, exemplified by "A and/or B," including either the A or B arrangement, or both A and B satisfied arrangement. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

The present invention provides a liquid returning device 100.

Referring to fig. 1 to 3, in an embodiment of the fluid returning apparatus 100 of the present invention, the fluid returning apparatus 100 is used for an invasive pressure sensor, the invasive pressure sensor (not shown) includes a blood sampling valve (not shown) and a pressure testing assembly (not shown), and the fluid returning apparatus 100 includes:

the liquid return cylinder 10 is provided with an accommodating cavity 111, the side wall of the liquid return cylinder 10 is further provided with a liquid inlet 113 and a liquid outlet 115, the liquid inlet 113 is communicated with the pressure testing assembly, and the liquid outlet 115 is communicated with the blood sampling valve; and the piston 30 comprises a piston head 31 and a piston rod 33, the piston head 31 is movably arranged in the accommodating cavity 111, the piston rod 33 extends into the accommodating cavity 111 and is connected with the surface of the piston head 31 departing from the liquid inlet 113 and the liquid outlet 115, and the piston rod 33 extends and retracts relative to the liquid return cylinder 10 to drive the piston head 31 to move in the accommodating cavity 111 so as to enable the pressure test liquid to flow out through the liquid outlet 115.

In the technical solution of an embodiment of the present invention, a containing cavity 111 is provided on a liquid return cylinder 10 of the liquid return device 100, the containing cavity 111 is used for storing pressure test liquid, a liquid inlet 113 and a liquid outlet 115 communicating with the containing cavity 111 are further provided on a side wall of the liquid return cylinder 10, a piston 30 is movably provided in the containing cavity 111, and a piston rod 33 is operated to control a piston head 31 in the containing cavity 111 to move relative to the containing cavity 111, so as to suck or extrude the pressure test liquid stored in the containing cavity 111. Before the invasive pressure sensor is used, all pipelines in the invasive pressure sensor need to be filled with pressure testing liquid, and at the moment, the piston rod 33 is pulled outwards, so that the pressure testing liquid in the pipeline channel can be sucked into the accommodating cavity 111 from the liquid inlet 113. After the blood sampling operation is completed through the blood sampling valve with the invasive pressure sensor, the piston rod 33 is pushed inwards again, so that the pressure test liquid in the accommodating cavity 111 flows out through the liquid outlet 115, at the moment, the pressure test liquid flowing out of the accommodating cavity 111 can return the blood retained in the catheter between the blood sampling valve and the blood vessel of the monitored person to the monitored person, the blood between the blood sampling valve and the monitored person is returned to the inside of the blood vessel of the monitored person by the pressure test liquid in the accommodating cavity 111, the waste phenomenon caused by the blood staying in the catheter is avoided, and the risk of infection caused by the blood left in the catheter is also avoided.

It should be noted that the material of the liquid return cylinder 10 is plastic, and the liquid inlet 113 and the liquid outlet 115 are both disposed on the side wall of the accommodating cavity 111, so as to ensure the strength of the liquid return apparatus 100. When the liquid returning device 100 is connected with a pressure testing assembly and a blood sampling valve, enough torque resistance can be provided, and the situation that the liquid returning device 100 is locally concentrated in stress to break is avoided.

Referring to fig. 1 to 3, in an embodiment of the present invention, the liquid return cylinder 10 has a length direction, the piston head 31 extends along the length direction of the liquid return cylinder 10, the piston rod 33 includes a main rod body 331 and two reinforcing rods 333, the main rod body 331 is disposed between the two reinforcing rods 333, and the reinforcing rods 333 and the main rod body 331 are disposed along the length direction of the piston head 31.

In the technical solution of an embodiment of the present invention, the liquid return cylinder 10 has a longitudinal direction, so that the liquid return cylinder 10 is substantially in a flat cylindrical structure, and the flat liquid return cylinder 10 is convenient for an operator to hold by hand. The shape of the piston head 31 is matched with the inner wall of the liquid return cylinder 10, so that the piston head 31 also has a length direction, and the piston rod 33 is convexly arranged on the surface of the piston head 31. In order to improve the strength of the piston rod 33, the piston rod 33 includes a main rod body 331 and a reinforcing rod 333, and the reinforcing rod 333 is provided to effectively improve the strength of the piston rod 33. The number of the reinforcement rods 333 is at least two, and the at least two reinforcement rods 333 are respectively located on both sides of the main rod body 331. The number of the reinforcing rods 333 is also plural, and the plural reinforcing rods 333 are symmetrically disposed at both sides of the main rod body 331. The reinforcing rod 333 and the main rod 331 are arranged along the length direction of the piston head 31, so that the piston head 31 can be uniformly stressed in the pushing process, and the condition that the flow rate of the pressure test liquid is influenced due to the inclination condition caused by uneven stress of the piston head 31 is avoided.

Specifically, the main rod 331 and the reinforcing rod 333 may be spaced apart from each other, so that the material of the piston rod 33 can be saved, and the material cost of the piston rod 33 can be reduced.

Referring to fig. 1 to 3, in an embodiment of the present invention, the piston rod 33 is further provided with a handle 37, and the handle 37 is connected to the main rod body 331.

In the technical scheme of an embodiment of the present invention, a fastening structure is formed at one end of the main rod body 331 away from the piston head 31, a fastening groove is formed inside the handle 37, and the handle 37 and the main rod body 331 are fixedly connected through the fastening and fastening groove. By arranging the handle 37, the contact area can be increased, and the operator can conveniently hold and operate the tool with hands.

In some embodiments, the main rod body 331 is further provided with a reinforcing rib (not shown) on the surface thereof, which can enhance the strength of the main rod body 331. It should be noted that a guiding structure (not labeled) is further protruded on the surface of the cover 13 away from the barrel 11, and the guiding structure guides the movement of the main rod body 331.

In some embodiments, the side wall of the end of the stiffener 333 facing away from the piston head 31 is further formed with an arc-shaped gripping portion (not labeled) to facilitate the operator's grip on the gripping portion to apply an external force to the stiffener 333. The side wall of the reinforcing rod 333 is further provided with a limit table, and when the limit table abuts against the cover 13, the limit table (not labeled) abuts against the inner surface of the cover 13, so that the outward pulling-out distance of the piston rod 33 is limited, and the excessive pulling-out situation is avoided.

In some embodiments, a material reducing region (not shown) is further disposed on a side of the reinforcing rod 333 near the main rod body 331, so that the reinforcing rod 333 has a shape that increases from near the piston head 31 to an end away from the piston head 31. Thus, the strength of the reinforcing rod 333 can be ensured, the reinforcing rod 333 can deform to a certain extent in the using process, the end portion of the reinforcing rod is conveniently arranged in the position-giving opening 131 in a penetrating mode, and hand feeling is improved.

Still the cover is equipped with a sealed plug 35 on the piston head 31, and sealed plug 35 and the inner wall butt of returning liquid section of thick bamboo 10 to improve the sealing performance of returning liquid section of thick bamboo 10 and sealed plug 35, also helped whole bed pressure sensor's pressurize effect simultaneously. The material of the sealing rubber plug 35 can be rubber or silica gel, and the shape of the sealing rubber plug 35 is matched with that of the piston head 31.

Referring to fig. 1 to fig. 3, in an embodiment of the present invention, the liquid inlet 113 and the liquid outlet 115 are oppositely disposed at an end of the liquid return cylinder 10 away from the piston rod 33.

In the technical solution of an embodiment of the present invention, the liquid inlet 113 and the liquid outlet 115 are disposed oppositely, that is, the liquid outlet 115 and the liquid inlet 113 are at the same horizontal line, which is convenient for the flow of the pressure test, so that the pressure test liquid in the accommodating cavity 111 is kept balanced. Moreover, the liquid inlet 113 and the liquid outlet 115 are oppositely arranged, and the processing and the forming are also convenient.

Referring to fig. 1 to 3, in an embodiment of the present invention, the liquid return cylinder 10 includes a cylinder body 11 and a cover body 13, the cylinder body 11 is formed with an accommodating groove (not labeled), and the liquid inlet 113 and the liquid outlet 115 are disposed away from an opening of the accommodating groove;

the cover body 13 can be detachably covered on the opening of the accommodating groove, and is surrounded with the accommodating groove to form the accommodating cavity 111, the cover body 13 is provided with a let position port 131, and the piston rod 33 at least partially penetrates through the let position port 131 and extends out of the accommodating cavity 111.

In one embodiment of the present invention, the liquid return cylinder 10 is configured to include a cylinder body 11 and a cover body 13, so as to facilitate installation of the piston 30. The number of the relief openings 131 in the cover 13 may be one, or a plurality of the relief openings may be provided at intervals. When the plurality of the clearance openings 131 on the cover 13 are arranged at intervals, the main rod 331 and the reinforcing rod 333 of the piston rod 33 are arranged at intervals, and the main rod 331 and the reinforcing rod 333 are respectively arranged in the clearance openings 131 in a penetrating manner, so that the size of the clearance openings 131 can be reduced, and the sealing effect in the accommodating cavity 111 can be improved.

Referring to fig. 3, in an embodiment of the present invention, a first position-limiting structure 112 is disposed at an opening of the accommodating groove of the cylinder 11, a second position-limiting structure 133 is disposed on an inner wall of the cover 13, and when the cover 13 covers the accommodating groove, the first position-limiting structure 112 and the second position-limiting structure 133 cooperate to limit the cover 13 to be detached from the cylinder 11.

In an embodiment of the present invention, the barrel 11 and the cover 13 are detachably connected by the first limiting structure 112 and the second limiting structure 133. The first limiting structure 112 and the second limiting structure 133 have various forms, for example, they may be a buckle and a slot, that is, one of the buckle and the slot is disposed on the outer side wall of the barrel 11, the other of the buckle and the slot is disposed on the cover 13, and the barrel 11 and the cover 13 are detachably connected through the north river of the buckle and the slot. The first limiting structure 112 and the second limiting structure 133 may also be other structures, for example, the outer side wall of the barrel 11 is provided with a flange (not marked), the inner side wall of the cover 13 is provided with a limiting rib (not marked), and when the cover 13 covers the accommodating groove, the limiting rib abuts against the flange to limit the cover 13 to slide out of the barrel 11. The first limit structure 112 and the second limit structure 133 have various forms, which are not listed here, as long as the cover 13 and the barrel 11 can be fixed together.

Referring to fig. 1 to 3, in an embodiment of the present invention, the liquid returning apparatus 100 further includes a protective cover 50, the protective cover 50 includes a fixing portion 55, an extending portion 53 and a handheld portion 51, which are sequentially connected, the protective cover 50 is sleeved on the liquid returning cylinder 10, the fixing portion 55 is fixed on an outer side wall of the cylinder 11, and the handheld portion 51 covers the cover 13 and an end of the piston rod 33 away from the piston head 31.

In an embodiment of the present invention, the material of the protective cover 50 is rubber, silicon gel, or other materials with elasticity, and the protective cover 50 has a substantially cylindrical structure with an opening. The fixing portion 55 is provided with an opening of the protection cover 50, it can be understood that the opening of the fixing portion 55 is smaller than the outer diameter of the cylinder 11, and when the protection cover 50 is sleeved on the outer surface of the cylinder 11, the fixing portion 55 can be fixed on the outer surface of the cylinder 11. The extension 53 is corrugated, when the piston rod 33 pushes, the extension 53 can contract and extend along with the movement of the piston rod 33, and the handheld portion 51 is sleeved at one end of the piston rod 33, which is far away from the piston head 31. The protection cover 50 can prevent external air from entering the accommodating cavity 111, and prevent the external air from polluting the inner wall of the accommodating cavity 111. Meanwhile, the use hand feeling of the operators can be improved.

Referring to fig. 1 to 3, in an embodiment of the present invention, a first connector 117 and a second connector 119 are formed on an outer sidewall of the liquid return cylinder 10 at the liquid inlet 113 and the liquid outlet 115, the liquid inlet 113 is connected to a pressure testing assembly, and the liquid outlet 115 is connected to the blood sampling valve.

In an embodiment of the present invention, the first connector 117, the second connector 119, and the liquid return cylinder 10 are integrated, and are made of plastic, and are integrally formed by injection molding, so that the strength of the first connector 117 and the second connector 119 can be ensured. The arrangement of the first connector 117 and the second connector 119 facilitates the connection between the pressure testing assembly and the blood sampling valve.

It should be noted that the pressure test assembly is connected to the first connector 117 via a conduit, and the blood collection valve is connected to the second connector 119 via a conduit. The guide tube is respectively sleeved on the outer side walls of the first connector 117 and the second connector 119, and it should be noted that, in order to ensure the firm connection between the guide tube and the first connector 117 and the second connector 119, a connecting thread (not shown) may be provided on the outer side walls of the first connector 117 and the second connector 119, or the outer diameters of the first connector 117 and the second connector 119 are decreased progressively from one end of the side wall of the liquid return cylinder 10 to the end far away from the side wall of the liquid return cylinder 10, so that the stability of the fixation between the guide tube and the first connector 117 and the second connector 119 can be ensured, and the separation between the guide tube and the first connector 117 and the second connector 119 is avoided.

Referring to fig. 1 to 3, in an embodiment of the present invention, the liquid returning device 100 further includes a fixing base 17, the fixing base 17 includes a fixing plate 171 and two fixing fasteners 175 protruding from a surface of the fixing plate 171, the two fixing fasteners 175 respectively fix the first connecting head 117 and the second connecting head 119 in a clamping manner, the fixing plate 171 is provided with a fixing hole 173, and the fixing plate 171 fixes the liquid returning device 100 through the cooperation of the connecting piece and the fixing hole 173.

In an embodiment of the present invention, the fixing base 17 is used to fix the whole reflow apparatus. The fixing base 17 includes a square fixing plate 171, fixing fasteners 175 are convexly disposed on two opposite sides of the fixing plate 171, end portions of the fixing fasteners 175 are bent to form a hook, and the first connector 117 and the second connector 119 are clamped inside the hook to fix the fixing base 17 and the liquid return cylinder 10. The fixing holes 173 of the fixing plate 171 are used to fix the entire fixing plate 171 to a test rack (not shown). The connecting member may be a positioning plate protruding from the testing frame, and the positioning plate is inserted into the fixing hole 173 to fix the entire fixing seat 17, so as to fix the entire liquid returning device 100 on the fixing plate 171. The fixing holes 173 may be plural and spaced between the two fixing fasteners 175, and the plural fixing holes 173 may improve the fixing firmness of the fixing seat 17. The fixing hole 173 may be a long strip shape, and may be adapted to the shape of the positioning plate (not shown), so as to improve the fixing firmness of the liquid returning device 100.

The invention further provides an invasive pressure sensor, which includes a blood sampling valve (not shown), a pressure testing component (not shown) and a liquid returning device 100, the specific structure of the liquid returning device 100 refers to the above embodiments, and since the invasive pressure sensor adopts all technical solutions of all the above embodiments, the invasive pressure sensor at least has all the beneficial effects brought by the technical solutions of the above embodiments, and details are not repeated herein.

Wherein, this liquid device 100 that returns first joint passes through the pipe and is connected with pressure test assembly, and the second joint that returns liquid device 100 passes through the pipe and is connected with the blood sampling valve, and the blood sampling valve deviates from one end of liquid device 100 that returns and is passed through remaining needle and monitored person's blood vessel intercommunication. Wherein, the one end that the pressure test subassembly deviates from liquid returning device 100 inserts pressure test liquid, and pressure test liquid fills whole pressure sensor's pipeline passageway. It can be understood that a chip (not shown) is arranged inside the pressure testing component, and the chip converts the pressure change in the catheter into an electric signal to be transmitted to the display terminal so as to obtain various physiological parameters of the blood pressure of the monitored person.

It should be noted that, when the blood sampling operation is performed through the blood sampling valve, the handle of the blood sampling valve is rotated to cut off the pipeline between the blood sampling valve and the fluid returning device 100, and when the blood sampling operation is completed, the handle of the blood sampling valve is rotated again to conduct the passage between the blood sampling valve and the fluid returning device 100, and at this time, the pressure test fluid in the fluid returning device 100 can return the blood between the monitored blood vessel and the blood sampling valve to the body of the monitored person.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.