CN104888310A - Blood return prevention infusion connector - Google Patents

Abstract

The invention provides a blood return prevention infusion connector which comprises an outer connector, an inner connecting seat and an elastic barrier piece. The outer connector is hermetically connected with the inner connecting seat, the elastic barrier piece is arranged between a liquid inlet of outer connector and a liquid outlet of the inner connecting seat, the periphery of the elastic barrier piece is connected with the inner wall of the liquid inlet, the elastic barrier piece is provided with a closed portion and a liquid though port, and the closed portion covers a liquid outlet of the inner connecting seat. By the aid of the blood return prevention infusion connector, the elastic barrier piece is fixed for the first time, one-way flow of liquid medicine is realized by only depending on deformation of the elastic barrier piece, the blood return can be prevented by the infusion connector even if liquid pressure is equal to human venous pressure or the pressure difference between the liquid pressure and the human venous pressure are smaller, the connector effectively solves the problem that a blood return prevention infusion connector cannot really function in preventing blood return in prior art, so that blood return is avoided even if an infusion person optionally walks or lifts an arm in the infusion process, and clinical application is more facilitated.

Description

An anti-reflux transfusion connector

technical field

The invention relates to a disposable medical device, in particular to an infusion joint with the function of preventing blood return, and belongs to the field of medical devices.

technical background

At present, the infusion sets used by domestic medical institutions for intravenous infusion are usually disposable infusion sets, which are medical consumables that have undergone aseptic treatment to establish a channel between the vein and the liquid medicine. Existing common infusion sets are generally made of needles (such as disposable intravenous infusion needles, intravenous indwelling needles, etc.), protective caps, infusion hoses, liquid medicine filters, flow rate regulators, Murphy's dropper, bottle stopper puncture It is mainly used for clinical gravity infusion, which plays a positive role in preventing cross-infection during infusion.

In clinical use, medical personnel insert the bottle stopper piercer of the infusion set into the infusion bottle, hang the infusion bottle on the infusion rod, exhaust the air and fill the entire infusion hose with liquid medicine, and then close the flow rate regulator to perform venipuncture After the needle puncture is fixed, the flow rate regulator can be opened, and the drip rate can be adjusted for infusion. Under the action of atmospheric pressure, the liquid medicine flows into the Murphy dropper along the infusion hose. When the pressure is greater than the venous pressure, the liquid in the infusion bottle flows into the vein along the infusion hose. However, during the infusion process or when there is a small amount of liquid medicine left in the infusion hose or when the liquid medicine is infused or stopped automatically, since the water column pressure at this time is lower than the venous pressure, if the flow rate regulator is not closed in time or the needle is pulled out , it will cause the patient's venous blood to flow back into the infusion tube, resulting in unexpected blood return. Once the blood returns, it will frighten the patient and cause the patient's worry and uneasiness, and it will cause the infusion hose to be unable to continue the infusion due to bubble embolism. Therefore, how to effectively solve this problem and its adverse consequences during clinical treatment has always been a thorny issue in the industry.

For this reason, many studies are dedicated to the development of infusion sets with anti-bleeding functions. For example, Chinese patent document CN203169710U discloses a kind of anti-bleeding device, which includes an anti-bleeding connector upper cover, a silica gel sheet, an anti-bleeding connector base, and an anti-bleeding connector upper cover and an anti-bleeding connector. The base of the anti-bleeding joint base is fixedly connected, and there is a cavity at the connection between the upper cover of the anti-bleeding joint and the base of the anti-bleeding joint, and the silicone sheet is arranged in the cavity. , the opening of the silicone sheet is close to the base of the anti-bleeding joint, and the bottom of the silicone sheet is provided with a circle of first protrusions. During the infusion process, under the pressure of the liquid medicine, the silicone sheet moves toward the base of the anti-bleeding connector in the cavity, the first protrusion is separated from the upper cover of the anti-bleeding connector, and the opening of the silicone sheet gently touches the anti-bleeding connector On the base, at this time, the liquid medicine can flow into the conduit connected to the base of the anti-bleed joint base from the opening part and the contact gap of the anti-bleed joint base; when the infusion is completed, the pressure inside the human body pushes the silicone sheet up, and the silicone sheet moves upward , the first protrusion is closely attached to the upper cover of the anti-bleeding joint, and this structure can prevent gas from entering, thus playing the function of preventing blood-reflux.

Obviously, the above technology relies on the up and down movement of the barrel-shaped silicone sheet in the cavity enclosed by the upper cover of the joint and the base to realize the function of the circulation of the medicinal liquid and block the blood. The interior is movable, not fixed, so that when the water column pressure in the Murphy's dropper is equal to the venous pressure or the pressure difference between the two is small, the silicone sheet will move to the middle of the cavity, and it will not contact the joint. The upper cover fits together and does not conflict with the joint base. At this time, the silicone sheet cannot block the backflow of blood, so that the anti-blood backflow device in this technology cannot effectively prevent blood backflow. In view of this, how to improve the structure of the anti-backflow infusion connector in the prior art to overcome the above-mentioned defects is an unresolved technical problem in the art.

Contents of the invention

The invention solves the problem that the anti-blood infusion joint in the prior art cannot effectively realize the anti-blood infusion function, and further provides an anti-blood infusion infusion joint that can effectively prevent blood backflow and has a simpler structure.

The technical scheme that the present invention realizes above-mentioned purpose is:

An anti-return blood transfusion connector, comprising an outer joint and an inner seat, the outer joint is in sealing connection with the inner seat,

It also includes an elastic barrier sheet provided with a sealing part and a liquid opening;

The sealing part covers the liquid outlet of the inner connection seat to restrict the flow of liquid at the liquid outlet;

The elastic barrier sheet is arranged between the liquid inlet of the outer joint and the liquid outlet of the inner connection seat, and its peripheral edge is connected with the inner wall of the liquid inlet.

Further, the projection of the liquid outlet of the inner connection seat on the elastic barrier sheet is located in the sealing part, so that the sealing part is not smaller than the liquid outlet.

Preferably, the closing part is arranged in the middle of the elastic barrier sheet, and the liquid opening is arranged around the closing part.

Further, a first liquid medicine channel is provided in the inner connection seat, and the first liquid medicine channel includes a liquid delivery section and a constriction section, and the diameter of the constriction section is gradually reduced along the flow direction of the liquid medicine to form the Liquid outlet.

Preferably, the cross-section of the necking section is a circle or a closed curve formed by two parallel line segments and two arcs connecting the end points on the same side of the two line segments. The connections form the closed curve.

Preferably, an exhaust port is also included, the exhaust port is arranged on the outer wall surface of the movable plug, the movable plug is embedded on the side wall of the first liquid medicine channel, and the movable plug is provided with Water-blocking air filter membrane.

Preferably, an annular boss is formed around the periphery of the necking section, and a liquid return space is formed between the inner wall of the annular boss and the outer wall of the necking section, and the liquid return space corresponds to the The liquid port of the elastic barrier.

Preferably, a second liquid medicine channel is arranged in the outer joint, and the second liquid medicine channel is divided into a liquid inlet section and a delivery section, and the diameter of the liquid inlet section gradually decreases along the flow direction of the liquid medicine, and the liquid inlet section The inlet of the segment is the liquid inlet of the external joint.

Preferably, a fixing piece is provided on the periphery of the elastic barrier, adapted to fix the elastic barrier between the liquid outlet of the inner socket and the liquid inlet of the outer joint.

Preferably, the fixing member is a circular platform, the circular platform is arranged above the annular boss, and its outer peripheral wall surface fits with the inner wall surface of the liquid inlet section of the outer joint, and runs through the upper and lower surfaces of the circular platform A third liquid medicine channel is provided, and the periphery of the elastic barrier sheet is fixed on the inner wall of the third liquid medicine channel.

In the anti-blood infusion joint of the present invention, the outer joint is sealed and connected with the inner joint seat, and an elastic barrier sheet with a sealing part and a liquid passage is provided between the liquid inlet of the outer joint and the liquid outlet of the inner joint seat, Make the periphery of the elastic barrier piece connect with the inner wall of the liquid inlet of the outer joint, and make the sealing part cover the liquid outlet of the inner joint seat; in this way, when the hose of the infusion set is filled with liquid medicine, hydraulic pressure will be formed, forcing the elastic barrier The sheet is deformed and away from the liquid outlet of the inner connection seat, thereby forming an infusion channel to realize the flow of medicinal liquid to the human body. As the infusion proceeds, when the hydraulic pressure is equal to or lower than the human body's venous pressure, a small amount of blood returns to make the elastic barrier sheet The liquid outlet of the inner connection seat is blocked by recovering the deformation, so as to effectively prevent the blood from flowing back into the hose of the infusion set, thereby avoiding the occurrence of unexpected blood return phenomenon.

Compared with the blood return preventing transfusion connector in the prior art, the blood return preventing transfusion connector of the present invention has the following advantages:

(1) The anti-blood return infusion connector of the present invention for the first time fixes the elastic barrier sheet that allows the liquid medicine to pass but prevents the blood from flowing back between the liquid inlet of the outer connector and the liquid outlet of the inner socket, and only relies on the elastic barrier sheet itself The elastic deformation of the liquid medicine can realize the one-way circulation of the liquid medicine. Compared with the anti-blood return infusion joint in the prior art, which needs to rely on the displacement of the silica gel sheet to block the blood backflow, the infusion joint of the present invention can be used even under the conditions of hydraulic pressure and human venous pressure. Even when the pressure difference between the two is equal or the pressure difference between the two is small, it can still prevent blood backflow, thereby effectively solving the problem that the anti-blood backflow infusion joint in the prior art cannot really play a role in preventing blood backflow, so that the infusion user can even Walking around or raising the arm at will will not cause blood back phenomenon, which is more convenient for clinical use.

(2) The anti-blood return transfusion connector of the present invention only needs to connect the periphery of the elastic barrier sheet with the inner wall of the liquid inlet of the outer joint, and make the sealing part of the elastic barrier sheet cover the liquid outlet of the inner connection seat. The cooperation between the elastic barrier sheet and the wall of the liquid outlet can realize the one-way circulation of the liquid medicine and prevent the blood from flowing back, making the structure of the present invention simpler and easier to process than the infusion joints in the prior art and making.

(3) The blood return anti-infusion joint according to the present invention is formed by arranging a first liquid medicine channel with a liquid delivery section and a constriction section in its inner socket, and the diameter of the constriction section is gradually reduced along the flow direction of the medicine liquid. The liquid outlet of the inner connection seat, so that when the liquid medicine reaches the elastic barrier sheet, the flow rate of the first liquid medicine channel is narrowed, so that the elastic barrier plate can be more forcefully forced to flow along the liquid medicine The direction is deformed and away from the liquid outlet of the inner connection seat, so that the liquid medicine can flow from the liquid opening opened on the elastic barrier sheet to the human body, so as to realize the circulation of the liquid medicine.

(4) In the anti-blood infusion connector of the present invention, a movable plug is embedded on the side wall of the first liquid medicine channel, and an exhaust port is provided on the outer wall of the movable plug, and a water-blocking air is provided in the movable plug. filter membrane, so that the infusion joint of the present invention also has the function of exhausting, once air is mixed in the infusion pipeline, when the air bubbles flow through the infusion joint of the present invention along with the liquid medicine, the air bubbles will automatically escape from the exhaust port , so as to effectively avoid the occurrence of air entering the human body, and also greatly simplify the exhaust operation during the infusion process.

(5) In the anti-blood return infusion connector of the present invention, an annular boss is arranged on the periphery of the constriction section surrounding the first liquid medicine passage, so that liquid return is formed between the inner wall of the annular boss and the outer wall surface of the constriction section. space, the liquid return space corresponds to the liquid opening of the elastic barrier sheet; this setting makes the elastic barrier sheet only contact with the wall of the liquid outlet of the inner connection seat, which is conducive to maintaining the surface flatness of the elastic barrier sheet, thereby ensuring that when there is a small amount When the blood flows back, the sealing part of the elastic barrier sheet can be closely attached to the wall surface of the liquid outlet of the inner connection seat, so as to better achieve the effect of preventing blood return.

(6) In the anti-return blood transfusion connector of the present invention, the fixing member is arranged on the periphery of the elastic barrier sheet, and the fixing member is preferably a round platform, which is arranged on the top of the annular boss, and its outer peripheral wall surface is connected with the liquid inlet of the outer joint. The inner wall surface of the segment fits together, and a third liquid medicine channel is provided through the upper and lower surfaces of the round table, and the peripheral edge of the elastic barrier sheet is fixed on the inner wall surface of the third liquid medicine channel, so that the outlet of the elastic barrier plate and the inner connection seat The liquid port can fit more closely, and the elastic barrier can be more firmly fixed between the liquid inlet of the outer joint and the liquid outlet of the inner joint, which is beneficial to enhance the anti-blood return effect of the elastic barrier.

(7) The anti-return blood transfusion connector of the present invention, its outer joint and inner joint seat can be standard 6 _: 100 conical joints, also can be 6 _: 100 spiral joints, make inner joint seat can be connected with liquid medicine filter, It can also be connected with a two-way with a tapered head; the outer joint can directly replace the infusion needle seat and be bonded to the thin tube of the infusion needle, or it can be connected to the thin tube of the infusion needle or assembled on the venous indwelling needle The three-way seat makes the infusion joint of the present invention universal, and can be directly assembled in various types of infusion sets such as precision filter infusion sets, bag type infusion sets, buret type infusion sets, self-stop infusion sets, and automatic exhaust infusion sets. Functional infusion sets and central venous catheters.

Description of drawings

Fig. 1 is a cross-sectional structure diagram of an embodiment of the anti-blood infusion connector of the present invention;

Fig. 2 is a structural diagram of an embodiment of the elastic barrier sheet in the anti-blood back transfusion connector of the present invention;

Fig. 3 is a structural diagram of another embodiment of the elastic barrier sheet in the anti-blood back transfusion connector of the present invention;

Fig. 4 is a cross-sectional structure diagram of another embodiment of the anti-blood return infusion connector according to the present invention;

Among them, the reference signs are as follows:

10-external joint; 11-liquid inlet; 12-second liquid medicine channel; 13-liquid inlet section; 14-transportation section; 20-internal socket; 21-liquid outlet; 23-liquid delivery section; 24-neck section; 25-buffer section; 26-annular boss; 30-elastic barrier piece; 31-closed part; ; 41-water blocking air filter membrane; 42-active plug.

Detailed ways

The anti-reflux transfusion connector provided by the present invention will be described in detail below in conjunction with specific examples.

The anti-return blood transfusion connector described in this embodiment, as shown in FIG. 1 , includes an outer joint 10, an inner joint seat 20 and an elastic barrier piece 30, wherein the sealing connection between the outer joint 10 and the inner joint seat 20, The elastic barrier sheet 30 is arranged between the liquid inlet 11 of the outer joint 10 and the liquid outlet 21 of the inner socket 20, and its periphery is connected with the inner wall surface of the liquid inlet 11; The elastic barrier sheet 30 has a sealing portion 31 and a liquid opening 32 , the sealing portion 31 covers the liquid outlet 21 of the inner socket 20 to restrict the flow of liquid at the liquid outlet 21 . The elastic barrier sheet 30 in this embodiment can be made of silica gel so that it can have good elasticity.

During the use of the blood return preventing infusion connector described in this embodiment, when the hose of the infusion set is filled with liquid medicine, hydraulic pressure will be formed, forcing the elastic barrier sheet 30 to deform and move away from the liquid outlet 21 of the inner socket 20, In this way, an infusion channel is formed to realize the flow of medicinal liquid to the human body. As the infusion progresses, when the hydraulic pressure is equal to or lower than the venous pressure of the human body, a small amount of blood returns to make the elastic barrier sheet 30 restore its deformation and block the outlet of the inner connection seat 20. The liquid port 21 is to effectively prevent the blood from flowing back into the flexible tube of the infusion set, so as to avoid the occurrence of unexpected blood return phenomenon, so that the infusion patient will not appear blood return phenomenon even if he walks around or raises his arm during the infusion process, which is very It is convenient for clinical use. In this embodiment, the projection of the liquid outlet 21 of the inner connection seat 20 on the elastic barrier sheet 30 is located in the sealing part 31, so that the sealing part 31 is not smaller than the liquid outlet 21, Such setting can better ensure the tight fit between the sealing part 31 of the elastic barrier 30 and the liquid outlet 21 of the inner socket 20, so that the anti-bleeding transfusion connector described in this embodiment has a better anti-bleeding effect.

As a preferred embodiment, the anti-return blood infusion connector described in this embodiment is provided with a first liquid medicine channel 22 in the inner socket 20, and the first liquid medicine channel 22 includes a liquid delivery section 23 and a constriction section 24. The diameter of the necking section 24 is gradually reduced along the flow direction of the liquid medicine to form the liquid outlet 21; in this way, when the liquid medicine reaches the elastic barrier sheet, the diameter of the first liquid medicine channel 22 is narrowed so that its flow rate increase, so that the elastic barrier sheet 30 can be more forcefully forced to deform along the flow direction of the liquid medicine and away from the liquid outlet 21 of the inner connection seat 20, so that the liquid medicine can pass through the liquid opening opened on the elastic barrier sheet 30 32 flow to the human body to realize the circulation of the medicinal liquid.

The cross-section of the necking section 24 in this embodiment can be a circle, or it can be a closed curve formed by two parallel line segments and two arcs connecting the same-side endpoints of the two line segments. The closed curve is formed end-to-end with the arc. Correspondingly, referring to FIG. 2 and FIG. 3 , the shape of the elastic barrier sheet 30 in this embodiment matches the shape of the cross-section of the constriction section 24 , and the sealing portion 31 is arranged on the elastic barrier sheet 30, the liquid opening 32 is arranged around the sealing part 31, and the shape of the liquid opening 32 can be a hole or a line.

Further, in order to make the liquid medicine flow from the inner connection seat to the outer joint more smoothly, as shown in Figure 4, the first liquid medicine channel 22 in the anti-blood return infusion connector of this embodiment is also provided with equal-caliber The buffer section 25, the inlet of the buffer section 25 is connected to the outlet of the necking section 24, and the cross-sectional shape of the buffer section 25 is consistent with the cross-sectional shape of the outlet of the necking section 24.

As a variable embodiment, the anti-return blood transfusion connector described in this embodiment is also formed with an annular boss 26 around the periphery of its necking section 24, and the inner wall of the annular boss 26 and the necking section 24 A liquid return space is formed between the outer walls, and the liquid return space corresponds to the liquid opening 32 of the elastic barrier sheet 30; in this way, the elastic barrier sheet 30 is only in contact with the wall surface of the liquid outlet 21 of the inner connection seat 20, which is beneficial to Maintain the flatness of the surface of the elastic barrier sheet, so as to ensure that when a small amount of blood flows back, the sealing part 31 of the elastic barrier sheet 30 can be closely attached to the wall surface of the liquid outlet 21 of the inner socket 20, so as to better prevent blood return Effect.

As a more preferred embodiment, in this embodiment, the external joint 10 is provided with a second liquid medicine channel 12, and the second liquid medicine channel 12 is divided into a liquid inlet section 13 and a delivery section 14, and the liquid inlet section 13 gradually decreases in diameter along the liquid medicine flow direction, and the inlet of the liquid inlet section 13 is the liquid inlet 11 of the outer joint 10 .

Further preferably, in order to make the elastic barrier sheet 30 fit more closely with the liquid outlet 21 of the inner connection seat 20, this embodiment also provides a fixing member 33 on the periphery of the elastic barrier sheet 30, so that the elastic The barrier sheet 30 is more firmly fixed between the liquid outlet 21 of the inner socket 20 and the liquid inlet 11 of the outer joint 10, which is beneficial to enhance the anti-bleeding effect of the elastic barrier sheet. The fixing member 33 in this embodiment can be selected as a circular platform, the circular platform is arranged above the annular boss 26, and its outer peripheral wall surface fits with the inner wall surface of the liquid inlet section 13 of the outer joint 10, and runs through The upper and lower surfaces of the round table are provided with a third liquid medicine channel, and the peripheral edge of the elastic barrier sheet 30 is fixed at any position on the inner wall of the third liquid medicine channel.

As an alternative implementation, the anti-return blood transfusion connector described in this embodiment further includes an exhaust port 40, and the exhaust port 40 is arranged on the outer wall surface of the movable plug 42, and the movable plug 42 is embedded in the On the side wall of the first liquid medicine channel 22, a water-blocking air filter membrane 41 is arranged in the movable plug 42, so that the infusion joint of this embodiment also has the function of exhausting, once the infusion line is mixed If there is air, then when the air bubbles flow through the infusion joint of the present invention along with the liquid medicine, the air bubbles will automatically escape from the exhaust port, thereby effectively avoiding the occurrence of air entering the human body, and also greatly simplifying the exhaust during the infusion process operate.

In addition, since the outer joint 10 and the inner connection seat 20 in this embodiment can be a standard 6:100 conical joint, or a 6:100 screw joint, the inner connection seat 20 can be connected to the liquid medicine filter, or It can be connected with the two-way with a tapered head, and the external joint 10 can directly replace the infusion needle holder, and be bonded to the thin tube of the infusion needle, or can be connected to the thin tube of the infusion needle or assembled on the side of the intravenous indwelling needle. On the three-way seat, therefore, the infusion connector described in this embodiment has universal applicability, and can be directly assembled on such as precision filter infusion set, bag type infusion set, burette type infusion set, self-stop infusion set, automatic exhaust infusion set And other functional infusion sets and central venous catheters.

Apparently, the above-mentioned embodiments are only examples for clear description, rather than limiting the implementation. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. And the obvious changes or changes derived therefrom are still within the scope of protection of the present invention.

Claims (10)

1. A transfusion joint for preventing blood return, comprising an outer joint (10) and an inner joint seat (20), the outer joint (10) is sealed and connected with the inner joint seat (20), It is characterized in that it also includes an elastic barrier sheet (30) provided with a closing part (31) and a liquid opening (32); The sealing part (31) covers the liquid outlet (21) of the inner socket (20) to restrict the flow of liquid at the liquid outlet (21); The elastic barrier sheet (30) is arranged between the liquid inlet (11) of the outer joint (10) and the liquid outlet (21) of the inner connection seat (20), and its periphery is in contact with the liquid inlet The inner wall of the port (11) is connected. 2. The anti-blood back infusion connector according to claim 1, characterized in that the projection of the liquid outlet (21) of the inner connection seat (20) on the elastic barrier (30) is located at the sealing part (31), so that the sealing part (31) is not smaller than the liquid outlet (21). 3. The anti-return blood transfusion connector according to claim 1 or 2, characterized in that, the sealing part (31) is arranged in the middle of the elastic barrier (30), and the liquid opening (32) surrounds the The sealing part (31) is set. 4. The anti-return blood transfusion connector according to any one of claims 1-3, characterized in that, a first medicinal liquid channel (22) is arranged in the inner socket (20), and the first medicinal liquid channel (22) includes a liquid delivery section (23) and a constriction section (24), the constriction section (24) is gradually reduced in diameter along the liquid medicine flow direction to form the liquid outlet (21). 5. The anti-return blood transfusion connector according to claim 4, characterized in that, the cross section of the necking section (24) is circular, or, It is a closed curve formed by two parallel line segments and two arcs connecting the end points on the same side of the two line segments, and the line segment and the arc are connected end to end to form the closed curve. 6. The anti-blood infusion connector according to claim 4 or 5, characterized in that, it also comprises an exhaust port (40), and the exhaust port (40) is arranged on the outer wall surface of the movable plug (42), so that The movable plug (42) is embedded on the side wall of the first liquid medicine channel (22), and a water-blocking air filter membrane (41) is arranged inside the movable plug (42). 7. The anti-return blood transfusion connector according to any one of claims 4-6, characterized in that, an annular boss (26) is also formed around the periphery of the necking section (24), and an annular boss (26) is formed on the periphery of the annular boss. A liquid return space is formed between the inner wall of (26) and the outer wall of the necking section (24), and the liquid return space corresponds to the liquid opening (32) of the elastic barrier piece (30). 8. The blood return preventing transfusion connector according to any one of claims 1-7, characterized in that, a second medicinal liquid channel (12) is arranged in the outer joint (10), and the second medicinal liquid channel ( 12) Divided into a liquid inlet section (13) and a delivery section (14), the liquid inlet section (13) gradually shrinks in diameter along the liquid medicine flow direction, and the inlet of the liquid inlet section (13) is the external joint ( 10) the liquid inlet (11). 9. The anti-return blood transfusion connector according to any one of claims 1-8, characterized in that, a fixing member (33) is arranged on the periphery of the elastic barrier sheet (30), and is suitable for fixing the elastic barrier sheet (30) is fixed between the liquid outlet (21) of the inner connecting seat (20) and the liquid inlet (11) of the outer joint (10). 10. The blood return preventing transfusion connector according to claim 9, characterized in that, the fixing member (33) is a circular platform, and the circular platform is arranged above the annular boss (26), and its peripheral wall surface is in contact with the said circular platform. The inner wall surfaces of the liquid inlet section (13) of the outer joint (10) are attached together, and a third liquid medicine channel is provided through the upper and lower surfaces of the circular platform, and the periphery of the elastic barrier sheet (30) is fixed on the first Three inner wall surfaces of the liquid medicine channel.