Quantitative fluid infusion and exhaust device for venous indwelling needle connector

Abstract

The invention discloses a quantitative fluid infusion and exhaust device for a venous indwelling needle connector, and relates to the technical field of medical instruments. The device comprises a base, a top seat and an extrusion mechanism, the base is detachably connected with the top seat, the top seat is provided with a U-shaped tube groove allowing an infusion tube to pass through, the top seat is connected with the extrusion mechanism, and the extrusion mechanism firstly blocks the upstream section of the infusion tube and then extrudes the downstream section of the infusion tube. By means of the three extrusion mechanisms, diversified implementation modes are provided, but the core of the three extrusion mechanisms is that the extrusion mechanisms have the ordered action logic of first blocking and then extrusion, and the design fundamentally ensures that an upstream backflow path is reliably cut off when downstream extrusion is carried out, so that the upstream backflow path is reliably cut off; by means of the structure, the amount of the discharged liquid is controlled and sealed between the liquid storage tank and the liquid storage tank, so that high-precision quantitative liquid supplementing is achieved, and uncertainty caused by strength and experience differences in manual operation is thoroughly eliminated.

Description

Technical Field

[0001] This invention belongs to the field of medical device technology, and in particular relates to a quantitative fluid replenishment and venting device for an indwelling intravenous catheter connector. Background Technology

[0002] In clinical nursing, indwelling intravenous catheters are widely used because they can reduce the pain of repeated punctures for patients, protect blood vessels, and reduce the workload of medical staff. However, when the syringe is withdrawn after injecting medication or sealing the catheter through the indwelling catheter connector (such as a needleless connector), the withdrawal of the syringe nipple will create a brief negative pressure inside the connector. This negative pressure may cause air to enter or, more commonly, draw blood from the patient's blood vessels back to the tip of the indwelling catheter, thereby causing coagulation and blockage, affecting subsequent treatment and increasing nursing risks.

[0003] Currently, the common clinical solution involves nurses manually squeezing the IV tubing at the same time or after removing the syringe, using the fluid inside to fill the space created by the syringe withdrawal, thus counteracting negative pressure and preventing backflow. However, this manual operation relies entirely on personal experience and feel, leading to difficulties in controlling the squeezing force and accurately quantifying the amount of fluid squeezed. Insufficient squeezing may result in inadequate fluid administration, failing to effectively create positive pressure for catheter sealing and still posing a risk of backflow; excessive squeezing wastes medication and may cause patient discomfort due to sudden excessive pressure. Therefore, there is an urgent need for an auxiliary device that enables standardized and quantifiable operation.

[0004] To overcome the shortcomings of manual operation, some solutions have been proposed in the existing technology as follows: For example, an existing published document (CN204766834U) discloses an indwelling needle with a squeeze-propelled positive pressure device. It has a positive pressure device with rollers on the extended tubing. The liquid is discharged by pushing the rollers to squeeze the tubing. Although this device provides a mechanical squeezing method, its rollers are usually designed to advance unidirectionally along a fixed trajectory. It has a single function and it is difficult to accurately control the amount of liquid discharged at one time. It cannot flexibly adapt to the differences caused by different syringe nipple volumes. For example, the existing public literature (CN105214167B) discloses a micro-positive pressure indwelling needle. By improving the internal structure of the indwelling needle connector (such as setting an elastic sealing plug), micro-positive pressure is automatically generated by material deformation when the needle is removed. Although this method achieves automation, the magnitude and duration of the positive pressure are limited by the material properties, and the structure is integrated into the connector, which is costly and cannot be used as a universal accessory with existing infusion tubing. Another example is an existing public document (CN105935458A) that discloses an infusion tubing for indwelling needles. It proposes a structure with special protrusions on the inner wall of the tubing, which relies on external clamps to squeeze and close the protrusions to block backflow. However, its anti-backflow effect depends on the special design of the tubing itself, has poor versatility, and also suffers from the problem of inaccurate squeezing volume.

[0005] In summary, the existing technology has the following main drawbacks: 1. Manual operation relies on experience, making precise quantitative control impossible and resulting in inconsistent results; 2. Existing mechanical extrusion devices (such as roller type) often have limited functionality, inconvenient or non-adjustable discharge volume, and poor adaptability; 3. Structural solutions integrated into connectors or hoses have low versatility, high cost, and may not provide ideal positive pressure.

[0006] To address these issues, we provide a quantitative fluid replacement and venting device for intravenous catheter connectors. Summary of the Invention

[0007] The purpose of this invention is to provide a quantitative fluid replacement and air release device for intravenous indwelling needle connectors. By setting a top seat that can be detachably connected to the infusion tubing, and connecting a squeezing mechanism with a specific structure to the top seat, it solves the technical problems of existing intravenous indwelling needles that rely on nurses to manually squeeze the infusion tubing for fluid replacement and air release after sealing or administering medication. These problems include the reliance on experience for operation, inaccurate squeezing volume, unreliable effect, and the limited functionality, non-adjustable quantitative volume, or poor versatility of some existing mechanical positive pressure devices.

[0008] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: The present invention is a quantitative fluid replacement and air release device for intravenous indwelling needle connector, comprising a base, a top seat and a squeezing mechanism. The top seat is detachably connected to the base, and the top seat has a U-shaped groove for accommodating the infusion tube. The squeezing mechanism is connected to the top seat. The squeezing mechanism first blocks the upstream section of the infusion tube and then squeezes the downstream section of the infusion tube.

[0009] The present invention is further configured such that the top seat is a No. 1 seat, and the extrusion mechanism matching the No. 1 seat is a No. 1 extruder.

[0010] The present invention is further configured such that the No. 1 extruder includes a slide, a No. 1 blocking block and a No. 1 extrusion block, with the No. 1 blocking block connected to one side of the bottom of the slide and the No. 1 extrusion block connected to the other side of the bottom of the slide. The top plate of the No. 1 seat is fixed with symmetrically arranged No. 1 guide plates on both sides. The center hole of the No. 1 seat top plate is threaded with a locking screw. The locking screw passes through the center hole of the slide and its bottom end is movably connected to a limit plate through a bearing. The two ends of the limit plate pass through the through grooves of the No. 1 guide plates on both sides. By adjusting the locking screw to change the height of the limit plate, the amount of liquid discharged in a single squeeze can be easily adjusted, realizing standardized and quantitative operation. In the initial state, neither the No. 1 blocking block nor the No. 1 squeezing block is in contact with the infusion tube, and the bottom end of the No. 1 blocking block protrudes more in the vertical direction than the No. 1 squeezing block (i.e., it is closer to the infusion tube).

[0011] The invention is further configured such that the first blocking block includes a blocking head, a second spring, and a guide rod. The blocking head is elastically connected to the bottom surface of the slide via a row of evenly distributed second springs. A row of guide rods is fixed to the slide, and each guide rod is inserted downward into the corresponding second spring. The top surface of the blocking head has a groove with a diameter larger than that of the guide rod, and the bottom end of the guide rod extends out of the corresponding groove.

[0012] The present invention is further configured such that the top seat is a No. 2 seat, and the extrusion mechanism matching the No. 2 seat is a No. 2 extruder.

[0013] The invention is further configured such that the second squeezer includes a wedge-shaped guide seat and rollers. Guide grooves are provided on both sides of the wedge-shaped guide seat. The rollers are movably connected to the bottom of the support. The support includes a handle rod and a U-shaped slide rod. The bottom part of the U-shaped slide rod passes through the central hole of the roller. The two top ends of the U-shaped slide rod are slidably connected in the guide grooves on both sides. A handle rod is fixed between the two top ends of the U-shaped slide rod. The movement of the support is restricted to translation along the direction of the guide groove (i.e., the support can only slide along the guide groove and will not rotate). In the initial state, the rollers are not in contact with the infusion tube.

[0014] The present invention is further configured such that sliders are fixed on both sides of the wedge-shaped guide seat, and grooves are provided on the inner walls of both sides of the seat plate of the second seat. The sliders on both sides of the wedge-shaped guide seat are slidably connected in the grooves on both sides of the second seat. A set of No. 1 springs is fixed at the bottom of the sliders on both sides of the wedge-shaped guide seat, and the No. 1 springs on both sides are respectively placed in the slide grooves on both sides of the No. 2 seat.

[0015] The present invention is further configured such that the top seat is a No. 3 seat, and the extrusion mechanism matching the No. 3 seat is a No. 3 extruder.

[0016] The present invention is further configured such that the No. 3 seat includes a side plate, a bottom plate and a No. 2 guide plate, and two symmetrically arranged bottom plates are fixed to the bottom of the side plate, and two No. 2 guide plates are fixed to each bottom plate; The No. 3 extruder includes a pressing plate, a No. 2 blocking block, and a No. 2 extrusion block, with the No. 2 blocking block and the No. 2 extrusion block slidably connected on the pressing plate; Two symmetrically arranged reset springs are fixed to the bottom of one side of the pressing plate. The bottom ends of the reset springs are fixed to the bottom plates on both sides. The pressing plate is movably connected to the No. 3 seat through a movable shaft.

[0017] The present invention is further configured such that the second blocking block includes a pressure head, a slide, and a tension spring. Two symmetrically arranged tension springs are fixed to the top of the pressure head, and the hanging ring at the top of each tension spring is movably hung on the slide. The second extrusion block includes a pressure head, a slide, and connecting rods. Two symmetrically arranged connecting rods are fixed on the top of the pressure head, and the hanging ring at the top of each connecting rod is movably hung on the slide. A movable groove is provided on one side of the pressing plate, and the slide of the second blocking block and the slide of the second squeezing block are slidably installed in the corresponding movable grooves. The second guide plate has a vertical guide limiting groove, and both ends of the pressure head are fixed with sliding blocks. The sliding blocks of the second extrusion block are slidably connected in the guide limiting grooves of the second guide plate on both sides, and the sliding blocks of the second blocking block are slidably connected in the guide limiting grooves of the second guide plate on both sides.

[0018] The present invention has the following beneficial effects: 1. This invention provides diverse implementation methods through three extrusion mechanisms, but their core lies in the orderly action logic of "first blocking, then extruding" of the extrusion mechanism. This design fundamentally ensures that the upstream return path has been reliably cut off when downstream extrusion is carried out, so that the amount of liquid discharged is the controlled portion of liquid sealed between the two, thereby achieving highly accurate quantitative liquid replenishment and completely eliminating the uncertainty caused by differences in force and experience in manual operation.

[0019] 2. The three different extrusion mechanisms of this invention can standardize and fix the volume of liquid discharged in one operation. The operator does not need to judge the force. He only needs to complete one complete pressing or rotating action to output a preset and constant amount of liquid. This significantly improves the standardization of the operation and the consistency of the results, effectively prevents blood backflow or air intake caused by insufficient liquid replenishment, and also avoids waste of medicine caused by excessive liquid replenishment.

[0020] 3. The device of the present invention is an independent external accessory that can be detachably clamped onto a standard infusion tubing via a base and a top seat. It does not require any modification to existing indwelling needles, infusion sets, or infusion tubing. It is highly versatile, low in cost, and easy to promote and use in clinical settings. The three different compression mechanisms provide different operating feel (such as rotary compression, push compression, and press compression) to meet the preferences of different usage scenarios and users.

[0021] 4. The three different compression mechanisms of this invention can automatically or easily reset after each operation, ready for the next use. The operation is convenient and smooth, greatly reducing the workload of nursing staff and improving the efficiency and reliability of tube sealing operations.

[0022] Of course, any product implementing this invention does not necessarily need to achieve all of the above advantages at the same time. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 Schematic diagram of a quantitative fluid resuscitation and venting device for use with indwelling intravenous catheter connectors Figure 1 .

[0025] Figure 2 for Figure 1 A schematic diagram of the explosion structure.

[0026] Figure 3 This is a schematic diagram of the connection structure between the first blocking block and the slide.

[0027] Figure 4 Schematic diagram of a quantitative fluid resuscitation and venting device for use with indwelling intravenous catheter connectors Figure 2 .

[0028] Figure 5 for Figure 4 A schematic diagram of the explosion structure.

[0029] Figure 6 for Figure 5 A schematic diagram of the middle roller.

[0030] Figure 7 Schematic diagram of a quantitative fluid resuscitation and venting device for use with indwelling intravenous catheter connectors Figure 3 .

[0031] Figure 8 for Figure 7 A schematic diagram of the explosion structure.

[0032] Figure 9 This is a schematic diagram of the structure of the second blocking block.

[0033] Figure 10 This is a schematic diagram of the structure of the second extrusion block.

[0034] The attached diagram lists the components represented by each number as follows: 100. Base; 200A, No. 1 seat; 210A, No. 1 guide plate; 220A, locking screw; 230A, limiting plate; 200B, No. 2 seat; 200C, No. 3 seat; 210C, side plate; 220C, bottom plate; 230C, No. 2 guide plate; 201, U-shaped groove; 202, sliding groove; 300A, No. 1 extruder; 310A, slide block; 320A, No. 1 blocking block; 321A, blocking head; 322A, No. 2 spring; 323A, guide rod; 330A, No. 1 extrusion block; 300B, No. 2 extruder; 310B, wedge-shaped guide seat; 311, slider; 312B, No. 1 spring; 313B, guide groove; 320B, roller; 321B, bracket; 3211B, handle rod; 3212B, U-shaped slide rod; 300C, No. 3 extruder; 310C, pressing plate; 311C, return spring; 312C, movable groove; 320C, No. 2 blocking block; 330C, No. 2 extrusion block; 301, pressure head; 302, slide; 303, tension spring; 304, connecting rod; 400. Infusion tubing. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Example 1, please refer to Figure 1 , Figure 4 and Figure 7 The present invention is a quantitative fluid replacement and venting device for intravenous indwelling needle connector, comprising a base 100, a top seat and a squeezing mechanism. The top seat is detachably connected to the base 100. The top seat has a U-shaped groove 201 for accommodating the passage of the infusion tube 400. The squeezing mechanism is connected to the top seat. The squeezing mechanism first blocks the upstream section of the infusion tube 400 and then squeezes the downstream section of the infusion tube 400.

[0037] This embodiment reveals the basic working principle of the quantitative fluid replenishment and venting device as follows: During operation, the infusion tube 400 is first placed into the U-shaped tube groove 201 of the top seat. Then, the squeezing mechanism is operated so that it first contacts the upstream section (near the infusion bottle end) of the infusion tube 400 and closes it, thereby achieving fluid blockage. Immediately afterwards, while maintaining the blocking state, the mechanism continues to work, squeezing the downstream section of the infusion tubing 400 (near the indwelling needle connector); Since the upstream has been reliably blocked, when the downstream tube is squeezed, the liquid inside is directed and quantitatively discharged to the indwelling needle connector, thereby precisely filling the gap inside the connector caused by the removal of the syringe, achieving the purpose of air release and preventing backflow of blood. After the operation is completed, the extrusion mechanism automatically resets, and the device can be reused or replaced.

[0038] Example 2, please refer to Figure 1 , Figure 2 and Figure 3 Based on Example 1, the top seat is No. 1 seat 200A, and the extrusion mechanism that matches No. 1 seat 200A is No. 1 extruder 300A. The No. 1 extruder 300A includes a slide 310A, a No. 1 blocking block 320A and a No. 1 extrusion block 330A. The No. 1 blocking block 320A is connected to one side of the bottom of the slide 310A, and the No. 1 extrusion block 330A is connected to the other side of the bottom of the slide 310A. On both sides of the top plate of the No. 1 seat 200A, there are symmetrically arranged No. 1 guide plates 210A. The center hole of the top plate of the No. 1 seat 200A is threaded with a locking screw 220A. The locking screw 220A passes through the center hole of the slide 310A and its bottom end is movably connected to the limit plate 230A through the bearing. The two ends of the limit plate 230A pass through the through grooves of the No. 1 guide plates 210A on both sides respectively. In the initial state, neither the first blocking block 320A nor the first squeezing block 330A is in contact with the infusion tube 400, and the bottom end of the first blocking block 320A protrudes more in the vertical direction than the first squeezing block 330A (i.e., it is closer to the infusion tube 400).

[0039] Specifically, the first blocking block 320A includes a blocking head 321A, a second spring 322A, and a guide rod 323A. The blocking head 321A is elastically connected to the bottom surface of the slide block 310A via a row of evenly distributed second springs 322A. A row of guide rods 323A is fixed to the slide block 310A. Each guide rod 323A is inserted downward into the corresponding second spring 322A. The top surface of the blocking head 321A has a groove with a diameter larger than that of the guide rod 323A. The bottom end of the guide rod 323A extends out into the corresponding groove.

[0040] In this embodiment, the extrusion mechanism is Extruder 300A, and its working principle is divided into two stages: preset quantity and extrusion execution, as detailed below: Preset quantitative stage: The operator first rotates the locking screw 220A according to the required drainage volume. The locking screw 220A is screwed into or out of the top plate of the first seat 200A through the thread, driving the limiting plate 230A connected to the bottom end through the bearing to rise or fall precisely along the through groove of the first guide plate 210A. This step presets the final position of the limiting plate 230A in the vertical direction, which determines the end point of the downward stroke of the slide 310A, thereby realizing quantitative control. Execution of the compression stage: After the preset quantitative stage is completed, the operator presses down on the slide block 310A to move it downwards. The slide block 310A moves downwards along the slide grooves 202 on both sides of the first seat 200A. At this time, the operation is carried out in two stages: First, the block is blocked: Since the bottom of the first blocking block 320A is more prominent and closer to the infusion tube 400 than the first squeezing block 330A in the initial state, when the slide 310A moves down, the first blocking block 320A will contact and completely flatten the upstream section of the infusion tube 400 first, thus reliably blocking the backflow of the liquid. Then, the squeezing process begins: the operator continues to press down the slide 310A. At this time, after the blocking head 321A inside the first blocking block 320A compresses the pipe, the second spring 322A at its top is compressed. The blocking head 321A can generate a slight elastic retraction relative to the slide 310A along the guide rod 323A. This design ensures that the slide 310A can continue to descend while maintaining the upstream blockage. The slide 310A continues to descend until it contacts and is blocked by the pre-set limit plate 230A. At this final position, the first squeezing block 330A flattens the downstream section of the infusion tube 400 to the predetermined degree. Since the upstream is always in a blocked state, the quantitative liquid sealed in the infusion tube 400 section is accurately discharged to the indwelling needle connector under squeezing, completing the fluid replenishment and air release. After the operation is completed, release the slide block 310A, and all components will reset with the help of the second spring 322A.

[0041] Example 3, please refer to Figure 4 , Figure 5 and Figure 6 Based on Example 1, the top seat is No. 2 seat 200B, and the extrusion mechanism that matches No. 2 seat 200B is No. 2 extruder 300B; The second extruder 300B includes a wedge-shaped guide seat 310B and a roller 320B. Guide grooves 313B are provided on both side walls of the wedge-shaped guide seat 310B. The roller 320B is movably connected to the bottom of the bracket 321B. The support 321B includes a handle 3211B and a U-shaped slide bar 3212B. The bottom part of the U-shaped slide bar 3212B passes through the central hole of the roller 320B. The two top ends of the U-shaped slide bar 3212B are slidably connected in the guide grooves 313B on both sides. The handle 3211B is fixed between the two top ends of the U-shaped slide bar 3212B. The movement of the support 321B is restricted to translation along the direction of the guide groove 313B (that is, the support 321B can only slide along the guide groove 313B and will not rotate). In the initial state, the rollers 320B are not in contact with the infusion tube 400.

[0042] Specifically, sliders 311 are fixed on both sides of the wedge-shaped guide seat 310B, and grooves 202 are opened on the inner walls of both sides of the seat plate of the second seat 200B. The sliders 311 on both sides of the wedge-shaped guide seat 310B are slidably connected in the grooves 202 on both sides of the second seat 200B.

[0043] Furthermore, a set of first springs 312B is fixed at the bottom of the sliders 311 on both sides of the wedge guide seat 310B, and the first springs 312B on both sides are respectively placed in the slide grooves 202 on both sides of the second seat 200B.

[0044] In this embodiment, the extrusion mechanism is the second extruder 300B, and its working principle is divided into two consecutive stages, as follows: In the first stage, the operator simultaneously grasps the handle 3211B and the outer shell of the wedge guide seat 310B and applies downward pressure. This force overcomes the supporting force of the first spring 312B installed in the slide groove 202 of the second seat 200B, pushing the wedge guide seat 310B to move vertically downward along the slide groove 202. At the same time, the bracket 321B and the roller 320B also descend vertically in sync. In this stage, there is no significant relative sliding between the handle 3211B and the guide groove 313B. The roller 320B first makes vertical contact with and completely crushes the upstream section of the infusion tube 400, forming a reliable blockage. The second stage, horizontal displacement and quantitative drainage: After the upstream pipe of the infusion tube 400 is compressed and blocked, the operator continues to apply downward force to the handle lever 3211B. At this time, since the infusion tube 400 has provided supporting reaction force and the first spring 312B is compressed and stored, the following changes will occur: Under the rebound force of the lower spring 312B, the wedge-shaped guide seat 310B tends to move slightly upward. However, since the upstream tubing of the infusion tube 400 has been crushed, this slight displacement is not enough to release the blockage. The blocking effect is maintained by the plastic deformation of the infusion tube 400 and the position of the roller 320B. When the operator applies downward pressure to the handle 3211B, the U-shaped slide bar 3212B of the support 321B is forced to slide downstream relative to the slightly upward or stationary wedge guide seat 310B within the inclined guide groove 313B of the wedge guide seat 310B. This relative motion is converted into the roller 320B being pushed downstream almost horizontally along the compressed infusion tube 400, thereby horizontally squeezing the closed liquid column formed upstream of the roller 320B in the first stage towards the downstream end of the infusion tube 400, thus accurately pushing the quantitative drug solution into the indwelling needle connector. The inclination and length of the guide groove 313B determine the horizontal stroke of the roller 320B, thereby fixing the volume of liquid discharged in each operation. After release, the first spring 312B drives the wedge guide seat 310B to reset, and drives the bracket 321B and the roller 320B to return to the initial position along the trajectory of the guide groove 313B and the slide 202.

[0045] Example 4, please refer to Figure 7 , Figure 8 , Figure 9 and Figure 10 Based on Example 1, the top seat is No. 3 seat 200C, and the extrusion mechanism that matches No. 3 seat 200C is No. 3 extruder 300C; The No. 3 seat 200C includes a side plate 210C, a base plate 220C and a No. 2 guide plate 230C. Two symmetrically arranged base plates 220C are fixed to the bottom of the side plate 210C, and two No. 2 guide plates 230C are fixed on each base plate 220C. The No. 3 extruder 300C includes a pressing plate 310C, a second blocking block 320C, and a second extrusion block 330C. The second blocking block 320C and the second extrusion block 330C are slidably connected on the pressing plate 310C. Two symmetrically arranged return springs 311C are fixed to the bottom of one side of the pressing plate 310C. The bottom ends of the return springs 311C are fixed to the bottom plates 220C on both sides. The pressing plate 310C is movably connected to the No. 3 seat 200C through a movable shaft.

[0046] Specifically, the second blocking block 320C includes a pressure head 301, a slide 302, and a tension spring 303. Two symmetrically arranged tension springs 303 are fixed on the top of the pressure head 301, and the hanging ring on the top of each tension spring 303 is movably hung on the slide 302. The second extrusion block 330C includes a pressure head 301, a slide 302, and a connecting rod 304. Two symmetrically arranged connecting rods 304 are fixed on the top of the pressure head 301, and the hanging ring on the top of each connecting rod 304 is movably hung on the slide 302.

[0047] Furthermore, a movable groove 312C is provided on one side of the pressing plate 310C, and the slide 302 of the second blocking block 320C and the slide 302 of the second pressing block 330C are respectively slidably installed in the corresponding movable groove 312C. The second guide plate 230C has a vertical guide limiting groove. Both ends of the pressure head 301 are fixed with sliding blocks. The sliding blocks of the second extrusion block 330C are slidably connected in the guide limiting grooves of the second guide plate 230C on both sides. The sliding blocks of the second blocking block 320C are slidably connected in the guide limiting grooves of the second guide plate 230C on both sides.

[0048] In this embodiment, the extrusion mechanism is the No. 3 extruder 300C, and the pressing plate 310C is movably connected to the side plate 210C of the No. 3 seat 200C via the top movable shaft, forming a lever mechanism. Its working principle is specifically divided into the following stages: First, it should be noted that when the operator presses down on the free end of the pressing plate 310C, it can rotate around the movable axis and move downward. The pressure head 301 of the second blocking block 320C and the second extrusion block 330C is strictly restricted within the vertical guide limiting groove of the second guide plate 230C by the sliding blocks at both ends. This determines that the final output motion of the pressure head 301 must be a purely vertical linear motion. The pressure head 301 is connected to the upper slide 302 via a tension spring 303 or a connecting rod 304, and the connection method is a movable hanging (i.e., rotatable connection). The carriage 302 is nested in the movable groove 312C of the pressing plate 310C. This design allows the carriage 302 a certain degree of sliding freedom within the movable groove 312C. Next, in the first stage, pressing the pressing plate 310C causes it to rotate and block the upstream flow: the operator presses down the pressing plate 310C, causing it to rotate around the movable axis. The movable groove 312C on the pressing plate 310C then tilts, and this tilting motion pushes the two slides 302. Since the slides 302 are movably connected to their respective tension springs 303 or connecting rods 304, and the latter are connected to the pressure head 301 which is strongly constrained by the vertical guide limiting groove, the slides 302 will adapt within the movable groove 312C. Sliding and adjusting the posture to ensure that the tension spring 303 or the connecting rod 304 remains as naturally horizontal or aligned as possible, thereby transmitting the vertical downward force most effectively. During this process, the second blocking block 320C moves vertically downward to first compress the upstream section of the infusion tube 400, completing the blocking. During this process, the tension spring 303 will be initially compressed. The slide 302 of the second compression block 330C also maintains the vertical force transmission state of the connecting rod 304 through adaptive sliding. However, during the blocking, the second compression block 330C does not contact the infusion tube 400. Next, in the second stage, the pressing plate 310C is continuously pressed down to squeeze the downstream section in a quantitative manner: after the upstream of the infusion tube 400 is blocked, the operator continues to press down the pressing plate 310C, and the second squeezing block 330C pushes its pressure head 301 to move down strictly along the vertical guide limiting groove through the rigid connecting rod 304, crushing the downstream section of the infusion tube 400. Since the upstream has been blocked, the liquid is squeezed out in a quantitative manner. At the end of the stroke of the movable groove 312C, an absolute hard limit is formed, which precisely determines the downward distance of the pressure head 301, thereby ensuring a constant discharge volume. After the pressure plate 310C is released, the return spring 311C reverses and resets it, and all components move in the opposite direction under constraint, returning to the initial state.

[0049] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

Claims

1. A quantitative fluid replacement and venting device for an indwelling intravenous needle connector, comprising a base (100), a top seat, and a squeezing mechanism; characterized in that: A top seat is detachably connected to the base (100). The top seat has a U-shaped groove (201) for accommodating the infusion tube (400) to pass through. A squeezing mechanism is connected to the top seat. The squeezing mechanism first blocks the upstream section of the infusion tube (400) and then squeezes the downstream section of the infusion tube (400).

2. The quantitative fluid replacement and air venting device for an indwelling intravenous needle connector according to claim 1, characterized in that, The top seat is seat number one (200A), and the extrusion mechanism that matches seat number one (200A) is extruder number one (300A).

3. A quantitative fluid replacement and air venting device for an indwelling intravenous needle connector according to claim 2, characterized in that, The first extruder (300A) includes a slide (310A), a first blocking block (320A) and a first extrusion block (330A). The first blocking block (320A) is connected to one side of the bottom of the slide (310A), and the first extrusion block (330A) is connected to the other side of the bottom of the slide (310A). The top plate of the No. 1 seat (200A) is fixed with symmetrically arranged No. 1 guide plates (210A) on both sides. The center hole of the top plate of the No. 1 seat (200A) is threaded with a locking screw (220A). The locking screw (220A) passes through the center hole of the slide (310A) and its bottom end is movably connected to a limit plate (230A) through a bearing. The two ends of the limit plate (230A) pass through the through grooves of the No. 1 guide plates (210A) on both sides respectively. In the initial state, neither the first blocking block (320A) nor the first squeezing block (330A) is in contact with the infusion tube (400), and the bottom end of the first blocking block (320A) protrudes more in the vertical direction than the first squeezing block (330A).

4. A quantitative fluid replacement and air venting device for an indwelling intravenous needle connector according to claim 3, characterized in that, The first blocking block (320A) includes a blocking head (321A), a second spring (322A), and a guide rod (323A). The blocking head (321A) is elastically connected to the bottom surface of the slide (310A) via a row of evenly distributed second springs (322A). A row of guide rods (323A) is fixed to the slide (310A). Each guide rod (323A) is inserted downward into the corresponding second spring (322A). The top surface of the blocking head (321A) has a groove with a diameter larger than that of the guide rod (323A). The bottom end of the guide rod (323A) extends out into the corresponding groove.

5. A quantitative fluid replacement and air venting device for an indwelling intravenous needle connector according to claim 1, characterized in that, The top seat is seat number two (200B), and the extrusion mechanism that matches seat number two (200B) is extruder number two (300B).

6. A quantitative fluid replacement and air venting device for an indwelling intravenous needle connector according to claim 5, characterized in that, The second extruder (300B) includes a wedge-shaped guide seat (310B) and a roller (320B). Guide grooves (313B) are provided on both side walls of the wedge-shaped guide seat (310B). The roller (320B) is movably connected to the bottom of a bracket (321B). The bracket (321B) includes a handle rod (3211B) and a U-shaped slide rod (3212B). The bottom side of the U-shaped slide rod (3212B)... The central hole of the roller (320B) is transversely inserted. The two ends of the U-shaped slide rod (3212B) are slidably connected in the guide grooves (313B) on both sides. A handle rod (3211B) is fixed between the two ends of the U-shaped slide rod (3212B). The movement of the bracket (321B) is restricted to translation along the direction of the guide groove (313B). In the initial state, the rollers (320B) do not contact the infusion tube (400).

7. A quantitative fluid replacement and air venting device for an indwelling intravenous needle connector according to claim 6, characterized in that, Both sides of the wedge-shaped guide seat (310B) are fixed with sliders (311), and both sides of the seat plate of the second seat (200B) are provided with sliding grooves (202). The sliders (311) on both sides of the wedge-shaped guide seat (310B) are slidably connected in the sliding grooves (202) on both sides of the second seat (200B). A set of No. 1 springs (312B) are fixed at the bottom of the sliders (311) on both sides of the wedge-shaped guide seat (310B), and the No. 1 springs (312B) on both sides are respectively placed in the grooves (202) on both sides of the No. 2 seat (200B).

8. A quantitative fluid replacement and air venting device for an indwelling intravenous needle connector according to claim 1, characterized in that, The top seat is a No. 3 seat (200C), and the extrusion mechanism that matches the No. 3 seat (200C) is a No. 3 extruder (300C).

9. A quantitative fluid replacement and air venting device for an indwelling intravenous needle connector according to claim 8, characterized in that, The No. 3 seat (200C) includes a side plate (210C), a base plate (220C) and a No. 2 guide plate (230C). Two symmetrically arranged base plates (220C) are fixed to the bottom of the side plate (210C), and two No. 2 guide plates (230C) are fixed on each base plate (220C) side by side. The third extruder (300C) includes a pressing plate (310C), a second blocking block (320C), and a second extrusion block (330C), with the second blocking block (320C) and the second extrusion block (330C) slidably connected on the pressing plate (310C). Two symmetrically arranged return springs (311C) are fixed to the bottom of one side of the pressing plate (310C). The bottom ends of the return springs (311C) are fixed to the bottom plates (220C) on both sides. The pressing plate (310C) is movably connected to the No. 3 seat (200C) through a movable shaft.

10. A quantitative fluid replacement and air venting device for an indwelling intravenous needle connector according to claim 9, characterized in that, The second blocking block (320C) includes a pressure head (301), a slide (302) and a tension spring (303). The top of the pressure head (301) is fixed with two symmetrically arranged tension springs (303), and the hanging ring at the top of each tension spring (303) is movably hung on the slide (302). The second extrusion block (330C) includes a pressure head (301), a slide (302) and a connecting rod (304). The top of the pressure head (301) has two symmetrically arranged connecting rods (304), and the hanging ring at the top of each connecting rod (304) is movably hung on the slide (302). The pressing plate (310C) has a movable groove (312C) on one side, and the slide (302) of the second blocking block (320C) and the slide (302) of the second pressing block (330C) are respectively slidably installed in the corresponding movable groove (312C); The second guide plate (230C) is provided with a vertical guide limiting groove. Both ends of the pressure head (301) are fixed with sliding blocks. The sliding blocks of the second extrusion block (330C) are slidably connected in the guide limiting grooves of the second guide plate (230C) on both sides. The sliding blocks of the second blocking block (320C) are slidably connected in the guide limiting grooves of the second guide plate (230C) on both sides.

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