A flushing device to prevent PICC catheter blockage

Abstract

The application discloses a kind of anti-PICC catheter blocking flush device, belong to medical equipment field, provide a kind of can realize long-term PICC catheter anti-blocking flush device;Including shell, liquid storage bag, gas storage bag and gas generating device;There is fixed-limiting cavity with cavity volume in the shell interior, liquid storage bag and gas storage bag are simultaneously arranged in the limiting cavity, and liquid storage bag and gas storage bag are made of flexible material and can be inflated and deformed sealed bag body structure;Liquid outlet port is provided on the liquid storage bag, and flow speed reducer is provided in communication with the liquid outlet port, and first luer joint is provided in communication with the liquid outlet port of flow speed reducer.The device is convenient, comfortable and safe for users;Effective anti-blocking flush operation can be realized to PICC catheter, can greatly reduce the risk of PICC catheter blockage, and does not need to be operated by professional medical staff in hospital, very convenient and effective.

Description

Technical Field

[0001] This invention relates to the field of medical devices, and more particularly to a flushing device for preventing PICC catheter blockage. Background Technology

[0002] A peripherally inserted central catheter (PICC) is a catheter inserted through a vein in the arm and placed one-third of the way down to the superior vena cava. This avoids direct contact between chemotherapy drugs and the veins in the arm. In addition, the high blood flow in the large veins can quickly dilute the chemotherapy drugs and prevent them from irritating the blood vessels.

[0003] Catheter obstruction caused by drug deposition or thrombosis is the most common non-infectious complication of PICC catheters. The most common cause is when a patient moves their arm vigorously or coughs, causing deformation of the catheter lumen and creating negative pressure, allowing blood to enter the catheter and causing thrombosis and obstruction.

[0004] Drug precipitation causing catheter blockage is due to low-pH drug precipitation and calcium phosphate crystals, and can be treated with 0.1% hydrochloric acid (HCl). Blockage caused by high-pH drugs can be effectively treated with sodium bicarbonate or sodium hydroxide. Finally, parenteral nutrition preparations may leave lipid residues that can block the catheter, which can be cleared with a 70% ethanol solution.

[0005] Thrombotic catheter occlusion includes fibrin sheath formation around the catheter tip or thrombosis within the catheter lumen, wall, or vein. Fibrin sheaths mostly form within two weeks of catheter insertion. These fibrin sheaths surrounding the catheter tip usually do not affect catheter function, but they can cause partial catheter occlusion. Intraluminal thrombosis is blood accumulating inside the catheter and adhering to the outer wall or catheter tip, often causing complete occlusion and accounting for about a quarter of catheter occlusions. Wall thrombosis not only obstructs the catheter tip but can also cause partial venous occlusion or progress to venous thrombosis.

[0006] Sometimes, the catheter may become completely blocked, making it impossible to flush it. More often, the catheter is only partially blocked, resulting in slow or intermittent fluid infusion.

[0007] Current clinical methods for maintaining PICC catheter patency include catheter flushing, using intra-catheter locking fluids such as heparin or saline, and installing a positive pressure displacement connector at the catheter insertion port. However, these methods all have their shortcomings, and catheter occlusion remains an unresolved issue in clinical practice.

[0008] Catheter flushing method:

[0009] Method 1: Flush with saline solution in a 10 ml syringe. Do not use a syringe smaller than 10 ml to clear the tubing, and do not apply excessive force, otherwise the catheter may rupture.

[0010] Method 2: Flushing using negative pressure technology. Connect the tee connector (without extension tubing) to the end of the PICC catheter. Connect a 10ml syringe containing 5000 U / mL urokinase (in 2ml of 0.9% saline) to one stopcock, and an empty syringe to the other stopcock. Turn the stopcock valve to open it for both the empty syringe and the catheter. Withdraw the plunger of the empty syringe to create a vacuum in the tubing. While maintaining aspiration, close the stopcock valve on the empty syringe and open the syringe containing urokinase; the urokinase will be drawn into the catheter. Attempt to draw blood after 60 minutes. If this is not possible, try flushing the tubing with 0.9% saline in a 10ml syringe.

[0011] Method 3: Same as Method 2, inject 25000 U / mL urokinase into the catheter, and withdraw it after 30 minutes. If the catheter is still not cleared, inject 100 ml of 0.9% sodium chloride solution containing 5000 units of urokinase over 6 hours.

[0012] The main drawbacks of catheter flushing are: to prevent catheter blockage, regular flushing and membrane replacement are required, such as once a week, and the membrane should be replaced promptly if it becomes loose. Frequent flushing can affect blood vessels. Histopathological examination has revealed that, in addition to thrombus formation, there is significant loss of vascular endothelial cells, inflammatory cell infiltration, edema, and severe degeneration of epidermal and chondrocytes, especially in the distal region of the puncture site, where there is more inflammatory cell infiltration than in the proximal region.

[0013] Intracatheter locking fluid method:

[0014] The purpose of an appropriate catheter locking solution is to maintain catheter patency when not in use and prevent backflow of blood caused by negative pressure within the catheter. Optimal locking solutions can prevent thrombus formation within the catheter and at the catheter tip, as well as fibrin adhesion and fibrin sheath formation.

[0015] For most low-concentration lockout solutions (e.g., 100 U / mL heparin), when the lockout solution is replaced, new lockout solution can be injected without aspiration or flushing with saline. Some lockout solutions may cause adverse reactions when injected into the bloodstream and must be aspirated before replacement, such as 5000 U / mL heparin.

[0016] Inadequacy of the locking fluid:

[0017] A comparative study of locking heparin and normal saline revealed that heparin offered little benefit in maintaining catheter patency. A secondary prognostic analysis showed that, apart from heparin-induced thrombocytopenia, there was no evidence that heparin was superior to normal saline in terms of safety.

[0018] The optimal time between two locking procedures when the catheter is not in use has not been well studied. Most guidelines typically recommend a period between 8 and 24 hours; however, in practice, PICC catheters are often locked for a period of one week or longer. Furthermore, due to patient arm movements, muscle compression of the catheter can cause blood to be drawn back from the catheter, leading to thrombus formation, rendering the locking solution ineffective in its occlusive function.

[0019] Install a positive pressure displacement connector at the catheter placement port:

[0020] Manual positive pressure technology is used to prevent blood from flowing back into the catheter. This is achieved by withdrawing the syringe from the injection site while still applying pressure to the syringe plunger when the last 0.5 ml of fluid is injected; alternatively, blood can be prevented from flowing back into the catheter by clamping it when the last 0.5 ml is injected. Currently, specialized positive pressure displacement connectors are available on the market to replace the manual positive pressure technology described above.

[0021] Disadvantages of positive pressure displacement connectors:

[0022] Clinical data showed no statistically significant difference in preventing catheter thrombosis when using a positive pressure displacement connector compared to the control group. Summary of the Invention

[0023] The technical problem solved by this invention is to provide a flushing device that can achieve long-term PICC catheter anti-blockage.

[0024] The technical solution adopted by this invention to solve its technical problem is: a flushing device for preventing PICC catheter blockage, comprising a housing, a liquid storage bag, a gas storage bag, and a gas generating device; the housing has a limiting cavity with a fixed volume, and the liquid storage bag and the gas storage bag are simultaneously disposed in the limiting cavity, and both the liquid storage bag and the gas storage bag are made of flexible material and are expandable and deformable sealed bag structures; the liquid storage bag is provided with a liquid outlet port, and a flow deceleration device is provided in communication with the liquid outlet port, and a first Luer connector is provided in communication with the liquid outlet end of the flow deceleration device, the first Luer connector passing through a perforation provided on the housing and used to communicate and cooperate with a corresponding second Luer connector on the PICC catheter; the gas generating device is connected to the gas storage bag, and the gas generating device can generate pressurized gas and supply it to the gas storage bag to cause the gas storage bag to expand and deform, thereby squeezing the liquid in the liquid storage bag and supplying it to the PICC catheter for flushing.

[0025] Furthermore, a filling port is provided in a continuous manner on the liquid storage bag, a self-sealing central partition is provided to cover the filling port, and a clearance opening is provided on the shell to expose the filling port.

[0026] Furthermore, the housing is composed of a lower housing and an upper cover connected by an openable mating structure. A limiting groove is provided in the lower housing corresponding to the limiting cavity, and positioning posts are provided around the limiting groove. The liquid storage bag and the gas storage bag are flat bag structures when not inflated. The liquid storage bag and the gas storage bag are stacked. Positioning rings are provided around the liquid storage bag and the gas storage bag, and the positioning rings are movably connected to the positioning posts in the corresponding positions.

[0027] Furthermore, a one-way valve is installed in the communication channel between the gas generator and the gas storage bag.

[0028] Furthermore, the liquid storage bag is made of polyvinyl chloride film bonded together by hot pressing, with a film thickness of 150 to 200 micrometers; the gas storage bag is made of polyethylene film bonded together by hot pressing, with a film thickness of 80 to 150 micrometers.

[0029] Furthermore, it also includes straps, with one strap on each side of the housing, and the two straps are equipped with buckles that can be fastened to each other.

[0030] Furthermore, the housing has an insertion hole for inserting and installing a gas generator; the gas storage bag has an air inlet end, and a connector is provided in communication with the air inlet end, with the connector located at the inner end of the insertion hole; the gas generator has an insertion head at the end that is inserted into the insertion hole; the insertion head and the connector are in a plug-in sealed fit, so that the gas generator and the gas storage bag can achieve plug-in sealed communication.

[0031] Furthermore, the gas generator is a self-generating device after being heated, and a storage chamber is provided inside the gas generator. The storage chamber contains a gas expansion agent, which is one of the following: trichlorofluoromethane (CFC-11), 1,2-dichlorotetrafluoroethane (HCFC-141b), cyclopentane, hexafluorobutane, pentafluoropropane (HFC-245fa), trifluoropropylene (Solstice LBA), and hexafluorobutene (HFO-1336mzz). The storage chamber is connected to the gas storage bag through a corresponding gas supply channel. After being heated, the gas generator can spontaneously and continuously generate gas and supply it to the gas storage bag, causing the gas storage bag to expand and deform, thereby squeezing the liquid in the liquid storage bag and continuously supplying it to the PICC conduit in a laminar flow manner.

[0032] Furthermore, the gas expanding agent is trifluoropropylene (Solstice LBA).

[0033] Furthermore, the fluid supply flow rate to the PICC catheter is between 0.1 ml / day and 1 ml / day.

[0034] Furthermore, the preferred liquid supply flow rate is 0.2 ml / day.

[0035] Furthermore, the gas generating device includes a metering gas supply device, which comprises an outer sleeve, an inner sleeve, a pressure cap, a gas guide column, a first spring, and a second spring. One end of the outer sleeve is sealed with a sealing plate, and one end of the gas guide column passes through the sealing plate into the outer sleeve. The other end of the gas guide column forms an insertion head, and a gas guide channel extending from both ends is provided within the gas guide column. The inner sleeve is fitted onto the portion of the gas guide column located inside the outer sleeve. The first spring is fitted onto the gas guide column, and both ends of the first spring are tightly abutted between the sealing plate of the outer sleeve and the end of the inner sleeve facing the sealing plate. The inner sleeve and the gas guide column are in a sealed fit that allows for reciprocating sliding along the length of the gas guide column. The end of the inner sleeve facing away from the sealing plate forms an air inlet after extending beyond the end of the gas guide column. A temporary air cavity is formed between the air inlet and the end of the air guide column; a limiting boss is provided in the middle of the outer peripheral wall of the inner sleeve; a second spring is sleeved on the inner sleeve, and one end of the second spring abuts against the limiting boss, while the other end of the second spring extends beyond the air inlet of the air guide column and connects to the pressure cap; a sealing surface is provided on the pressure cap facing the air inlet; in its natural state, there is a gap between the sealing surface of the pressure cap and the air inlet; when pressure is applied to the pressure cap towards the air inlet, the pressure cap overcomes the elastic force of the second spring, allowing the sealing surface of the pressure cap to press tightly against the air inlet for a sealing fit; and when further pressure is applied to the pressure cap, it overcomes the elastic force of the first spring, causing the pressure cap and the inner sleeve to move along the air guide column to compress the temporary air cavity and allow the gas in the temporary air cavity to be discharged from the air guide channel.

[0036] Furthermore, a second outer sleeve is provided on the pressure cap, one end of which is connected to the pressure cap, and the second outer sleeve is fitted onto the second spring; a first limiting ring is provided on the end of the second outer sleeve away from the pressure cap, and the first limiting ring cooperates with the limiting boss to limit the limiting boss inside the second outer sleeve.

[0037] Furthermore, a second limiting ring is provided at the end of the outer sleeve away from the sealing plate, and a second limiting boss is provided at the end of the inner sleeve facing the outer sleeve. The second limiting ring and the second limiting boss cooperate to limit the second limiting boss inside the outer sleeve.

[0038] Furthermore, the volume of the temporary air chamber under natural conditions is set to 0.05 to 0.2 ml, preferably 0.05 ml.

[0039] Furthermore, the gas generating device also includes an electric actuator, which comprises an electromagnetic induction coil, a power supply, and a control circuit. A telescopic push rod is located inside the electromagnetic induction coil. The control circuit controls the power supply to generate a regular pulse current, which is applied to the electromagnetic induction coil to cause the telescopic push rod to perform a regular reciprocating telescopic motion. The outer end of the telescopic push rod is driven by a pressure cap, so that the reciprocating telescopic motion of the push rod drives the pressure cap to reciprocate. The regular pulse current is preferably set to start once every 12 hours, each pulse consisting of 6 pulses, each pulse lasting 0.5 seconds, with a 0.5-second interval between consecutive pulses.

[0040] Furthermore, the liquid supplied to the PICC catheter by the corresponding reservoir bag for each pulse is a turbulent fluid with a Reynolds number (Re) greater than 1000.

[0041] The beneficial effects of this invention are as follows: The device is convenient, comfortable, and safe for users; it enables effective anti-blockage flushing of PICC catheters, greatly reducing the risk of PICC catheter blockage. Patients can operate the device themselves or it can be fully automated, eliminating the need for professional medical personnel to perform the flushing at a hospital, making it very convenient and effective. Furthermore, the device can be worn on the patient's arm and maintain long-term communication with the PICC catheter's indwelling port. Because it can perform flushing periodically or as needed, it prevents blood reflux and thrombus formation that could block the PICC catheter, even after any arm movement or significant body movement. Additionally, the entire device can be detachable, with an openable shell for attaching and detaching the corresponding fluid reservoir, gas reservoir, and gas generator. This allows for flexible configuration of the appropriate fluid reservoir, gas reservoir, and gas generator based on the patient's actual medication needs, meeting the requirements of various patients. Furthermore, the entire device of this invention can be equipped with gas generating devices of different functions as needed to achieve different flushing function requirements, such as continuous flushing for a long time, or flushing at intervals, and can be configured for manual or automatic flushing operations. Additionally, the liquid storage bag and gas storage bag in this invention can be configured as completely separate and independent bag structures, which simplifies the corresponding bag structure, facilitates manufacturing, further reduces the production cost of the device, and promotes the widespread application of the entire device. Attached Figure Description

[0042] Figure 1 This is an overall schematic diagram of the device described in this invention;

[0043] Figure 2A three-dimensional schematic diagram illustrating a specific structural example of the device described in this invention;

[0044] Figure 3 for Figure 2 An explosion diagram;

[0045] Figure 4 for Figure 2 Top view;

[0046] Figure 5 for Figure 4 Sectional view of section AA;

[0047] Figure 6 The side view is shown in section 2, and a strap is provided.

[0048] Figure 7 for Figure 2 A schematic diagram showing the hidden upper cover.

[0049] Figure 8 for Figure 7 Top view;

[0050] Figure 9 This is a schematic diagram of the self-generating device after being heated in this invention;

[0051] Figure 10 This is a schematic diagram of the metering gas dispensing device in the present invention, shown in its natural state;

[0052] Figure 11 for Figure 10 A schematic diagram under pressure;

[0053] Figure 12 This is a schematic diagram of the electric device in the present invention;

[0054] Figure 13 This is a schematic diagram of the flow rate reduction device in this invention;

[0055] Figure 14 The mean incidence of PICC catheter-related upper extremity venous thrombosis in a group of cancer patients in a test experimental group;

[0056] Figure 15 The experimental results show the relationship between single pulse duration and protein recovery rate;

[0057] Figure 16 The experimental results show the relationship between the interval between two consecutive pulses and the protein recovery rate.

[0058] Figure 17 The experimental results show the relationship between continuous rinsing time and protein recovery rate;

[0059] Figure 18 This is a temperature and pressure curve of some of the gas expansion agents in this invention;

[0060] The components in the diagram are labeled as follows: 1. Housing; 2. Liquid storage bag; 3. Gas storage bag; 4. Gas generator; 5. Limiting cavity; 6. Flow deceleration device; 7. First Luer connector; 8. Perforation; 9. PICC conduit; 10. Second Luer connector; 11. Filling port; 12. Self-sealing central partition; 13. Relief port; 14. Lower housing; 15. Upper cover; 16. One-way groove; 17. Positioning post; 18. Positioning retaining ring; 19. One-way valve; 20. Strap; 21. Insertion hole; 22. Connector; 23. Insertion head; 24. Storage cavity; 25. Quantitative gas filling device. 25. Outer sleeve; 26. Inner sleeve; 27. Pressure cap; 28. Air guide column; 29. ​​First spring; 30. Second spring; 31. Sealing plate; 32. Air guide channel; 33. Air inlet; 34. Temporary air chamber; 35. Limiting boss; 36. Sealing surface; 37. Electric device; 38. Electromagnetic induction coil; 39. Power supply; 40. Control circuit; 41. Telescopic push rod; 42. Fastener; 43. Rear cover; 44. Sealing ring; 45. Second outer sleeve; 46. Second limiting boss; 47. Second limiting ring; 48. First limiting ring; 49. Detailed Implementation

[0061] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0062] It should be noted that if the present invention involves directional terms such as up, down, left, right, front, and back, these terms are used to describe the relative positional relationship between components and are not specific to the absolute position of related components or the positional relationship between components. They are only used to explain the relative positional relationship and movement of components in a specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0063] As shown in the figure, the flushing device for preventing PICC catheter blockage according to the present invention includes a housing 1, a liquid storage bag 2, a gas storage bag 3, and a gas generating device 4. The housing 1 has a limiting cavity 5 with a fixed volume. The liquid storage bag 2 and the gas storage bag 3 are simultaneously disposed within the limiting cavity 5, and both the liquid storage bag 2 and the gas storage bag 3 are made of flexible material and are expandable and deformable sealed bag structures. The liquid storage bag 2 has a liquid outlet port, and a flow deceleration device 6 is disposed in communication with the liquid outlet port. A first Luer connector 7 is disposed in communication with the liquid outlet end of the flow deceleration device 6. The first Luer connector 7 passes through a perforation 8 on the housing 1 and is used to communicate and cooperate with a corresponding second Luer connector 10 on the PICC catheter 9. The gas generating device 4 is connected to the gas storage bag 3 and can generate pressurized gas to supply to the gas storage bag 3, causing the gas storage bag 3 to expand and deform, thereby squeezing the liquid in the liquid storage bag 2 and supplying it to the PICC catheter 9 for flushing.

[0064] The device of the present invention has a fixed volume of the limiting cavity 5. Therefore, when gas is supplied into the gas storage bag 3, causing the gas storage bag 3 to expand and deform, it will squeeze the liquid storage bag 2. After the corresponding liquid substance is injected into the liquid storage bag 2 in advance, the liquid in the liquid storage bag 2 can be discharged from its outlet port by means of the squeezing action of the gas storage bag 3, so as to supply it to the PICC catheter to achieve the anti-blockage flushing function of the PICC catheter and prevent blockage.

[0065] The flow rate reduction device 6 is located at the outlet port of the liquid storage bag 2, and its function is to limit the flow rate and velocity of the liquid discharged from the liquid storage bag 3. Specifically, the flow rate reduction device 6 in this invention can be configured as a conical nozzle structure; as shown in the attached figure. Figure 13 As shown, the angle θ of its conical nozzle can be specifically set to 10 degrees, with the smaller end of the nozzle serving as the input port and the larger end as the output port. More specifically, the outlet port of the aforementioned flow deceleration device 6 is directly connected to a standard first Luer connector 7. This first Luer connector 7 is used to connect to a second Luer connector 10 installed on the PICC conduit 9, thereby connecting the storage bag 2 in the device described in this invention to the PICC conduit. Without loss of generality, the first Luer connector 7 and the second Luer connector 10 should be mutually compatible Luer connector assemblies. Generally, a set of matching Luer structure assemblies includes a male Luer connector and a female Luer connector, or also referred to as a male threaded Luer connector and a female threaded Luer connector; specifically, in this invention, the first Luer connector 7 and the second Luer connector 10 should be a set of matching Luer connectors.

[0066] The reservoir bag 2 in this invention is a bag structure used to store drug solutions. In use, the drug in the reservoir bag 2 is continuously or intermittently supplied to the PICC catheter to achieve a flushing operation. Specifically, the drug solution inside can be a commonly used drug solution for flushing PICC catheters, such as physiological saline, uricase, heparin, or dimethyl sulfoxide.

[0067] More specifically, in this invention, a filling port 11 is connected to the reservoir bag 2, and a self-sealing central partition 12 is provided to cover the filling port 11. A clearance opening 13 is provided on the housing 1 to expose the filling port 11. Thus, before use, the reservoir bag 2 can be an empty bag. Only when needed is the corresponding drug solution added to the reservoir bag 2 via the filling port 11 using a syringe. The self-sealing central partition 12 facilitates the insertion of the syringe needle and ensures the self-sealing of the filling port 11 after the drug solution is added; specifically, the self-sealing central partition 12 can be a structure such as a rubber stopper.

[0068] More specifically, the shell 1 in this invention can be configured to be composed of a lower shell 14 and an upper cover 15 connected by a switchable mating structure. At the same time, a limiting groove 16 is provided in the lower shell 14 corresponding to the limiting cavity 5, and positioning posts 17 are provided around the limiting groove 16. The liquid storage bag 2 and the gas storage bag 3 are flat bag structures when not inflated. The liquid storage bag 2 and the gas storage bag 3 are stacked. Positioning rings 18 are provided around the liquid storage bag 2 and the gas storage bag 3, and the positioning rings 18 are movably sleeved with the positioning posts 17 in the corresponding positions. This facilitates the assembly and disassembly of the housing 1. The liquid storage bag 2 and the gas storage bag 3 are also preferably detachable and separately installed inside the housing 1. The advantages of this arrangement are: the housing 1, liquid storage bag 2, and gas storage bag 3 can be completely separate, allowing for independent production, processing, and transportation. They are then assembled before use, making production, storage, and transportation more convenient and simpler, and assembly easier; thus effectively reducing the production cost of the device. Furthermore, regarding the specific detachable structure of the lower housing 14 and the upper cover 15, quick assembly and disassembly can be achieved through a toothed structure. Corresponding protrusions can be provided on the outer walls of the lower housing 14, and corresponding hooks can be provided on the inner walls of the upper housing 15. The lower housing 14 and the upper cover 15 can be assembled and disassembled through the engagement of the protrusions and hooks. Alternatively, the upper housing 15 can be hinged to the lower cover 14 on one side, with a snap-fit ​​structure on the opposite side to achieve the aforementioned switchable function. Furthermore, for the liquid storage bag 2 and the gas storage bag 3, since the installation and positioning are limited by the corresponding positioning rings 18 and positioning posts 17, their assembly and disassembly are very convenient. Moreover, the positioning rings 18 are allowed to slide relative to the positioning posts 17 during the expansion of the bag body, further reducing the impact of bag installation on bag expansion. Referring to the attached drawings, the housing 1 and its internal limiting cavity 5 are roughly rectangular, with a positioning post 17 at each of the four corners of this rectangular shape for limiting the installation of the positioning rings 18 on the liquid storage bag 2 and the gas storage bag 3.

[0069] Furthermore, for both the liquid storage bag 2 and the gas storage bag 3, this invention requires that both be made of flexible materials capable of expansion and deformation, so that the drug solution can be extruded and supplied through expansion and deformation. Specifically, in this invention, the liquid storage bag 2 can be made of polyvinyl chloride film bonded together by hot pressing, with a film thickness of 150 to 200 micrometers; while the gas storage bag 3 can be made of polyethylene film bonded together by hot pressing, with a film thickness of 80 to 150 micrometers. Of course, theoretically, both can also be made of other materials capable of the above-mentioned expansion and deformation.

[0070] Furthermore, to prevent backflow of gas within the gas storage bag 3, a one-way valve 19 can be installed in the communication channel between the gas generating device 4 and the gas storage bag 3, so that gas can only be supplied from the gas generating device 4 to the gas storage bag 3 without backflow. (See attached diagram) Figure 1 The diagram shows the location of the one-way valve 19. More specifically, in this invention, the one-way valve 19 can be integrated with the gas generating device 4, meaning that the one-way valve 19 can be connected and installed at the corresponding exhaust port of the gas generating device 4.

[0071] Additionally, refer to the appendix Figure 6 As shown in the diagram, the present invention further includes straps 20, with one strap 20 on each side of the housing 1, and fasteners 43 on the two straps 20 that can be fastened together. This allows the entire device to be secured to the patient's arm via the straps 20, facilitating the connection between the device and the PICC catheter, and ensuring proper fixation after connection. This allows for long-term carrying by the patient after installation and reduces the impact of patient activity on the stability of the device connection.

[0072] Furthermore, the gas generating device 4 can be further configured as a detachable split structure relative to the housing 1. Correspondingly, the housing 1 has an insertion hole 21 for inserting and installing the gas generating device 4. The gas storage bag 3 has an air inlet end, and a connector 22 is provided communicating with the air inlet end, positioned at the inner end of the insertion hole 21. An insertion head 23 is provided on the end of the gas generating device 4 that is inserted into the insertion hole 21. The insertion head 23 and the connector 22 are in a plug-in sealed fit, enabling the gas generating device 4 and the gas storage bag 3 to achieve a plug-in sealed connection. That is, the insertion head 23 and the insertion hole 21 are in a detachable plug-in fit, and maintain a sealed connection after plugging in. More preferably, a corresponding rubber sealing ring can be fitted on the insertion head 23, so that when the insertion head 23 is inserted into the connector 22 for plugging in, the corresponding rubber sealing ring ensures a sealing effect after plugging in. Of course, without loss of generality, the connector 22 should be provided with a corresponding channel to communicate with the gas storage bag 3; and the insert 23 should also be provided with a corresponding channel to communicate with the part of the gas generating device 4 that can generate airflow, so as to ensure that after the insert 23 is inserted into the connector 22 and connected, the gas generating device 4 can supply gas to the gas storage bag 3.

[0073] The gas generating device 4 in this invention is used to generate pressurized gas and supply it to the gas storage bag 3, causing the gas storage bag 3 to expand and deform, thereby squeezing the liquid in the liquid storage bag 2 and supplying it to the PICC conduit 9 for flushing. Specifically, the gas generating device 4 in this invention can adopt various device structures that can achieve the above-mentioned functional requirements. Three specific implementation schemes are provided below:

[0074] In the first embodiment, the gas generator 4 is a self-generating device after being heated. Correspondingly, a storage chamber 24 is provided inside the gas generator 4, and a gas expansion agent is provided in the storage chamber 24. The gas expansion agent is one of the following: trichlorofluoromethane (CFC-11), 1,2-dichlorotetrafluoroethane (HCFC-141b), cyclopentane, hexafluorobutane, pentafluoropropane (HFC-245fa), trifluoropropylene (Solstice LBA), and hexafluorobutene (HFO-1336mzz). The storage chamber 24 is connected to the gas storage bag 3 through a corresponding gas supply channel. After being heated, the gas generator 4 can spontaneously and continuously generate gas and supply it to the gas storage bag 3, causing the gas storage bag 3 to expand and deform, thereby squeezing the liquid in the liquid storage bag 2 and continuously supplying it to the PICC conduit 9 in a laminar flow manner. By employing the aforementioned gas expanding agents, the advantage is that spontaneous expansion can be achieved at relatively low temperatures, generating pressurized gas which is then supplied to the gas storage bag. Especially under ambient temperatures and temperatures close to human skin, such as approximately 20–40 degrees Celsius, it can continuously generate pressurized gas at appropriate pressure, meeting the requirement of continuously and slowly supplying pressurized gas to the gas storage bag 3, thereby achieving the condition of continuously and slowly squeezing the liquid storage bag 2 to supply flushing fluid to the PICC catheter. (See attached...) Figure 18 The figure shows the temperature and pressure curves of four expansion agents: trichlorofluoromethane (CFC-11), 1,2-dichlorotetrafluoroethane (HCFC-141b), pentafluoropropane (HFC-245fa), and trifluoropropylene (Solstice LBA). The figure shows that at approximately 20–40 degrees Celsius, these four gases can generate a pressure of approximately 50–250 kPa. This pressure, when combined with a flow rate reduction device 6 of appropriate specifications, can ultimately achieve the requirement of continuously and slowly supplying a certain flow rate of liquid to the PICC conduit 9.

[0075] For the specific structure of the aforementioned self-generating device after heating, please refer to the appendix. Figure 9 As shown in the figure, it may specifically include a cylindrical body, with a corresponding insertion head 23 at one end. Inside the cylindrical body is a storage chamber 24, and the other end of the cylindrical body is an open structure. This open structure is opened and closed via a corresponding rear cover 44. Furthermore, to ensure a tight seal when the rear cover 44 is closed, a sealing ring 45 is provided, as shown in the attached figure. In this way, an expanding agent can be easily added to the storage chamber 24 by opening the rear cover 44.

[0076] More preferably, when the gas generating device 4 is a self-generating device after heating, the liquid supply flow rate to the PICC conduit 9 is preferably set between 0.1 ml / day and 1 ml / day. Specifically, it needs to be matched with a flow rate reduction device 6 of the corresponding specification according to the temperature and pressure curve of the selected gas expansion agent to achieve the above-mentioned control of the liquid supply flow rate. In this way, for the device of the present invention to operate continuously for 30 days, the total liquid volume required in its storage bag 2 will be approximately 3 to 30 ml, which is sufficient. More preferably, the liquid supply flow rate can be set to 0.2 ml / day; in this case, the liquid volume required in the storage bag 2 for continuous operation for 30 days is approximately 6 ml. Of course, in actual use, it should be considered that a small amount of liquid in the storage bag 2 cannot be completely drained, so the liquid added to the storage bag 2 initially should be slightly larger than the actual required liquid volume.

[0077] In addition, referring to the physical properties of several gas expanding agents shown in Table 1 below, and in conjunction with the attached... Figure 18 As shown; the preferred gas expanding agent in this invention is trifluoropropylene (Solstice LBA), which has the following advantages: a boiling point of 19°C, non-flammable, non-toxic to medical materials in the device, decomposes after 28 days in the air, and is environmentally friendly; the pressure is 1.83 bar at body temperature (approximately 37°C) and 1.36 bar at 25°C; the temperature gradient change is relatively small, with the pressure increasing by approximately 0.02 bar for every 1°C change in temperature, and the change range is 0.012-0.032 bar in the 0-40°C range, which will not generate strong high-pressure stress on the power storage bag 3 of the device; moreover, 1 ml of trifluoropropylene liquid can evaporate and expand to a volume of 20 ml, thus providing a relatively constant temperature and pressure gas power source, meeting the requirements for the gas expanding agent in this invention.

[0078] Table 1 Physical properties of several gas expansion agents

[0079]

[0080] Additionally, refer to the appendix Figure 17 As shown in the figure, in order to verify the effect of the continuous laminar flow method achieved by the self-generating device after heating in this invention to flush the PICC catheter 9, relevant experiments were conducted, and the experimental results showed the effect of continuous flushing time on protein recovery rate; it can be seen that using continuous laminar flow to flush the catheter can effectively ensure the anti-blockage purpose of the PICC catheter.

[0081] The second option is detailed in the appendix. Figure 10 and attached Figure 11As shown, the gas generating device 4 of the present invention includes a metering gas supply device 25, which includes an outer sleeve 26, an inner sleeve 27, a pressure cap 28, a gas guide column 29, a first spring 30, and a second spring 31. One end of the outer sleeve 26 is sealed with a sealing plate 32, and one end of the gas guide column 29 is sealed and inserted into the outer sleeve 26 through the sealing plate 32. The other end of the gas guide column 29 forms an insertion head 23, and a gas guide channel 33 is provided inside the gas guide column 29, passing through both ends. The inner sleeve 27 is fitted onto the outer sleeve 26. On a portion of the air guide column 29 located inside the outer sleeve 26, a first spring 30 is sleeved on the air guide column 29, with both ends of the first spring 30 tightly abutting between the sealing plate 32 of the outer sleeve 26 and the end of the inner sleeve 27 facing the sealing plate 32; the inner sleeve 27 and the air guide column 29 are in a sealed fit that allows for reciprocating sliding along the length of the air guide column 29. An air inlet 34 is formed at the end of the inner sleeve 27 facing away from the sealing plate 32 after extending beyond the end of the air guide column 29, and the air inlet 34 is positioned between the end of the air guide column 29 and the end of the air guide column 29. A temporary air cavity 35 is formed; a limiting boss 36 is provided in the middle of the outer peripheral wall of the inner sleeve 27; a second spring 31 is sleeved on the inner sleeve 27, with one end of the second spring 31 pressing against the limiting boss 36, and the other end of the second spring 31 extending beyond the air inlet 34 of the air guide column 29 and connecting to the pressure cap 28; a sealing surface 37 is provided on the pressure cap 28 facing the air inlet 34; in the natural state, due to the elastic force of the second spring 31, there is a gap between the sealing surface 37 of the pressure cap 28 and the air inlet 34. The gap allows air to enter the temporary air chamber 35. When pressure is applied to the pressure cap 28 towards the air inlet 34, the pressure cap 28 overcomes the elastic force of the second spring 31, allowing the sealing surface 37 of the pressure cap 28 to press tightly against the air inlet 34 for a sealing fit. Further pressure is applied to the pressure cap 28, overcoming the elastic force of the first spring 30, causing the pressure cap 28, along with the inner sleeve 27, to move along the air guide column 29 to compress the temporary air chamber 35 and allow the gas in the temporary air chamber 35 to be discharged from the air guide channel 33. The pressure applied to the pressure cap 28 is as follows: Figure 11 The downward pressure force F shown can theoretically be applied manually or by a specialized mechanism. However, generally speaking, during the application of pressure to the gland 28, it is required that the gland 28 first overcome the sealing surface 37 of the second spring 31 to achieve a tight seal with the air inlet 34, and then drive the inner sleeve 27 to move along the air guide column 29 to compress the temporary air chamber 35 and expel the gas. Therefore, there are corresponding requirements for the initial elasticity of the first spring 30 and the second spring 31. Specifically, the pressure required to compress the first spring 30 to achieve a tight seal between the sealing surface 37 and the air inlet 34 should not be greater than the pressure required to compress the second spring and drive the inner sleeve 27 to move along the air guide column 29.

[0082] Furthermore, more specifically, a second outer sleeve 46 can be provided on the pressure cap 28. One end of the second outer sleeve 46 is connected to the pressure cap 28, and the second outer sleeve 46 is sleeved on the second spring 31. A first limiting ring 49 is provided on the end of the second outer sleeve 46 away from the pressure cap 28. The first limiting ring 49 cooperates with the limiting boss 36 to limit the limiting boss 36 within the second outer sleeve 46. This facilitates the guiding and limiting installation of the pressure cap 28, and also achieves the pre-tightening compression effect on the second spring 31. Similarly, in this invention, a second limiting ring 48 can be provided on the outer sleeve 26 at the end away from the sealing plate 32, and a second limiting boss 47 can be provided on the inner sleeve 27 at the end facing the outer sleeve 26. The second limiting ring 48 and the second limiting boss 47 cooperate to limit the second limiting boss 47 within the outer sleeve 27. This can limit the inner sleeve 27 and also achieve the pre-tightening compression effect on the first spring 30.

[0083] Furthermore, the aforementioned metered gas supply device 25 can generate a metered amount of compressed gas during each pressurization operation and supply it to the gas storage bag 3 through the gas guide channel 33; and the metered amount of gas generated each time is actually related to the size of the temporary gas chamber 35. Therefore, in order to meet the requirement of generating flushing liquid flow rate to the PICC catheter in this invention, it is preferred that the volume of the temporary gas chamber 35 in the natural state is set to 0.05 to 0.2 ml, so that after each pressurization of the metered gas supply device 25, 0.05 to 0.2 ml of pressurized gas can be supplied to the gas storage bag 3, thereby ultimately achieving the goal of supplying approximately 0.05 to 0.2 ml of flushing liquid to the PICC catheter with each pressurization. More specifically, the volume of the temporary gas chamber 35 can be set to 0.05 ml or 0.1 ml, etc. The aforementioned natural state refers to the state of the metered gas supply device 25 without being subjected to corresponding pressure, that is, the state of being attached to the gas chamber. Figure 10 The state shown; while the volume of the temporary air chamber 35 refers to the space between the air inlet 34 of the temporary air chamber 35 and the corresponding end face of the air guide column 29.

[0084] The third option is to further install an electric device 38 on the basis of the second option. This electric device 38 can then perform regular, timed, and / or frequencyd automatic pressure on the metering device 25 to generate metered, timed, and / or frequencyd pulse flushing of the PICC conduit. This avoids the need for manual pressing when only the metering device 25 is installed, thus avoiding uncontrollable problems such as the number of presses, pressing speed, pressing interval, and pressing time caused by manual operation. More specifically, the electric device 38 includes an electromagnetic induction coil 39, a power supply 40, and a control circuit 41. A telescopic push rod 42 is provided inside the electromagnetic induction coil 39. The control circuit 41 controls the power supply 40 to generate a regular pulse current, which is applied to the electromagnetic induction coil 39 to cause the telescopic push rod 42 to produce a regular reciprocating telescopic motion. The outer end of the telescopic push rod 42 is in a transmission engagement with the pressure cap 28, so that the reciprocating telescopic motion of the push rod 42 drives the pressure cap 28 to reciprocate. Of course, without loss of generality, the control circuit 41 is preferably configured as an adjustable device for controlling the corresponding pulse current parameters, so as to facilitate adjustment according to actual conditions. Furthermore, without loss of generality, the electric device 38 described above can also be other existing pulse action devices, mechanisms, etc., capable of automatically applying quantitative, timed, and / or frequencyd pressure to the metered gas dispensing device 25.

[0085] More specifically, in this invention, the regularly scheduled pulse current is preferably set to activate once every 12 hours, with each pulse consisting of 6 pulses, each pulse lasting 0.5 seconds, and an interval of 0.5 seconds between consecutive pulses. This allows the control circuit 41 to automatically control the timing, activating the metering gas supply device 25 every 12 hours to apply six pulses. Each applied force will cause the metering gas supply device 25 to supply a certain amount of gas to the gas storage bag 3. If the volume of the temporary gas chamber 35 is set to 0.05 ml, each pulse will actually supply approximately 0.05 ml of gas to the gas storage bag 3, thereby actually causing the liquid storage bag 2 to supply approximately 0.05 ml of flushing fluid to the PICC catheter for flushing. Thus, through the aforementioned flushing operation activating once every 12 hours, each time consisting of 6 pulses, approximately 0.3 ml of flushing fluid will be supplied to the PICC catheter every 12 hours, achieved through six intermittent pulse flushing, rather than a single 0.3 ml flushing fluid application. The reason for employing a multi-stage pulse flushing method in this invention is based on the laws of fluid mechanics. For the same volume of flushing fluid, a single continuous flush or multiple intermittent flushing produces a better flushing effect than a single flush. Furthermore, the flushing effect of turbulent fluid generated by each pulse is actually better than that of laminar flow. Therefore, in summary, this invention further enhances the flushing effect on the PICC conduit 9 by supplying a turbulent fluid with a Reynolds number (Re) greater than 1000 to the corresponding storage bag 2.

[0086] Furthermore, when pressurized gas is supplied using the metering gas supply device 25, the short duration of each pressurization operation results in a faster liquid flow rate discharged from the storage bag 2, thus achieving a rapid pulse flushing effect on the PICC catheter. This rapid pulse flushing effect differs from the continuous, slow laminar flow flushing effect generated by the self-generating device after heating, as described in this invention. With rapid pulse flushing, the number of flushes, the flushing time interval, and the flow rate of the flushing liquid all affect the flushing effect; therefore, please refer to the attached... Figure 15 and appendix Figure 16 As shown, to verify the flushing effect of the pulse flushing method in this invention on the PICC catheter 9, relevant experiments were conducted to obtain experimental results on the effect of single pulse flushing time and pulse interval time on protein recovery rate. Furthermore, based on the experimental results, this invention optimizes the combination parameters with the relatively best flushing effect, namely the parameters disclosed in this invention: a single pulse duration of 0.5 seconds and an interval of 0.5 seconds between consecutive pulses.

Claims

1. A flushing device for preventing PICC catheter blockage, characterized in that: The device includes a housing (1), a liquid storage bag (2), a gas storage bag (3), and a gas generating device (4). Inside the housing (1) is a limiting cavity (5) with a fixed volume. The liquid storage bag (2) and the gas storage bag (3) are simultaneously disposed within the limiting cavity (5), and both the liquid storage bag (2) and the gas storage bag (3) are made of flexible material and are capable of expansion and deformation as sealed bag structures. A filling port (11) is provided on the liquid storage bag (2), and a self-sealing central partition (12) covers the filling port (11). A clearance port (13) is provided on the housing (1) to expose the filling port (11). A liquid outlet port is provided on the liquid storage bag (2), and a liquid outlet port is connected to the liquid outlet port. A flow deceleration device (6) is provided, and a first Luer connector (7) is provided in communication with the liquid outlet end of the flow deceleration device (6). The first Luer connector (7) passes through a perforation (8) provided on the housing (1) and is used to communicate and cooperate with the corresponding second Luer connector (10) on the PICC conduit (9). A gas generator (4) is connected to a gas storage bag (3). The gas generator (4) can generate pressurized gas and supply it to the gas storage bag (3) so that the gas storage bag (3) expands and deforms, thereby squeezing the liquid in the liquid storage bag (2) and supplying it to the PICC conduit (9) for flushing. A one-way valve is provided in the communication channel between the gas generator (4) and the gas storage bag (3). 19); An insertion hole (21) for inserting and installing a gas generator (4) is provided inside the housing (1); An air inlet is provided on the gas storage bag (3), and a connector (22) is provided in communication with the air inlet, the connector (22) being located at the inner end of the insertion hole (21); An insertion head (23) is provided on the end of the gas generator (4) that is inserted into the insertion hole (21); the insertion head (23) and the connector (22) are in a plug-in sealed fit, so that the gas generator (4) and the gas storage bag (3) can achieve plug-in sealed communication; the gas generator (4) is a self-generating device after being heated, and a gas generator (4) is provided inside the gas generator (4). There is a storage chamber (24), and a gas expansion agent is provided in the storage chamber (24). The gas expansion agent is one of trichlorofluoromethane, 1,2-dichlorotetrafluoroethane, cyclopentane, hexafluorobutane, pentafluoropropane, trifluoropropylene and hexafluorobutene. The storage chamber (24) is connected to the gas storage bag (3) through a corresponding gas supply channel. The gas generating device (4) can spontaneously and continuously generate gas after being heated and supply it to the gas storage bag (3) so that the gas storage bag (3) expands and deforms, thereby squeezing the liquid in the liquid storage bag (2) and continuously supplying it to the PICC conduit (9) in a laminar flow manner. The liquid supply flow rate to the PICC conduit (9) is between 0.1 ml / day and 1 ml / day.

2. The flushing device for preventing PICC catheter blockage as described in claim 1, characterized in that: The housing (1) is composed of a lower housing (14) and an upper cover (15) connected by a switchable mating structure. A limiting groove (16) is provided in the lower housing (14) corresponding to the limiting cavity (5). A positioning post (17) is provided around the limiting groove (16). The liquid storage bag (2) and the gas storage bag (3) are flat bag structures when not expanded. The liquid storage bag (2) and the gas storage bag (3) are stacked. A positioning ring (18) is provided around the liquid storage bag (2) and the gas storage bag (3). The positioning ring (18) and the positioning post (17) in the corresponding position are movably connected.

3. The flushing device for preventing PICC catheter blockage as described in claim 1, characterized in that: The liquid storage bag (2) is made of polyvinyl chloride film by hot pressing and bonding, with a film thickness of 150 to 200 micrometers; the gas storage bag (3) is made of polyethylene film by hot pressing and bonding, with a film thickness of 80 to 150 micrometers; it also includes straps (20), with one strap (20) on each side of the shell (1), and the two straps (20) are provided with buckles (43) that can be fastened to each other.

4. The flushing device for preventing PICC catheter blockage as described in claim 1, characterized in that: The liquid supply flow rate is 0.2 ml / day.

5. A flushing device for preventing PICC catheter blockage as described in claim 1, characterized in that: The gas generating device (4) is replaced by a self-generating device after heating with the following structure: including a metering gas supply device (25), the metering gas supply device (25) including an outer sleeve (26), an inner sleeve (27), a pressure cap (28), a gas guide column (29), a first spring (30) and a second spring (31); one end of the outer sleeve (26) is sealed with a sealing plate (32), one end of the gas guide column (29) is sealed and inserted into the outer sleeve (26) through the sealing plate (32) of the outer sleeve (26), and the other end of the gas guide column (29) forms an insertion head (23), and a through-hole is provided in the gas guide column (29) from both ends. The air guide channel (33); the inner sleeve (27) is fitted on a portion of the air guide column (29) located inside the outer sleeve (26), the first spring (30) is fitted on the air guide column (29) and the two ends of the first spring (30) are tightly abutted between the sealing plate (32) of the outer sleeve (26) and the end of the inner sleeve (27) facing the sealing plate (32); the inner sleeve (27) and the air guide column (29) are a sealed fit that can reciprocate relative to each other along the length direction of the air guide column (29), and the end of the inner sleeve (27) facing away from the sealing plate (32) forms an air inlet after extending beyond the end of the air guide column (29). (34), and a temporary air cavity (35) is formed between the air inlet (34) and the end of the air guide column (29); a limiting boss (36) is provided in the middle of the outer peripheral wall of the inner sleeve (27); the second spring (31) is sleeved on the inner sleeve (27), and one end of the second spring (31) abuts against the limiting boss (36), and the other end of the second spring (31) extends beyond the air inlet (34) of the air guide column (29) and is connected to the pressure cap (28); a sealing surface (37) is provided on the pressure cap (28) facing the air inlet (34); in the natural state, the pressure cap (28) seals... There is a gap between the cover (37) and the air inlet (34); when pressure is applied to the cover (28) toward the air inlet (34), the cover (28) overcomes the elastic force of the second spring (31) and can make the sealing surface (37) of the cover (28) press and seal with the air inlet (34); and when pressure is further applied to the cover (28), it overcomes the elastic force of the first spring (30) and makes the cover (28) together with the inner sleeve (27) move along the air guide column (29) to compress the temporary air chamber (35) and make the gas in the temporary air chamber (35) discharged from the air guide channel (33).

6. The flushing device for preventing PICC catheter blockage as described in claim 5, characterized in that: A second outer sleeve (46) is also provided on the cap (28). One end of the second outer sleeve (46) is connected to the cap (28), and the second outer sleeve (46) is sleeved on the second spring (31). A first limiting ring (49) is provided on the second outer sleeve away from the cap. The first limiting ring (49) cooperates with the limiting boss (36) to limit the limiting boss (36) inside the second outer sleeve (46). A second limiting ring (48) is provided on the outer sleeve (26) away from the sealing plate (32). A second limiting boss (47) is provided on the inner sleeve (27) facing the outer sleeve. The second limiting ring (48) cooperates with the second limiting boss (47) to limit the second limiting boss (47) inside the outer sleeve (26). The volume of the temporary air chamber (35) in the natural state is set to 0.05 to 0.2 ml.

7. A flushing device for preventing PICC catheter blockage as described in claim 6, characterized in that: The volume of the temporary air chamber (35) under natural conditions is set to 0.05 ml.

8. A flushing device for preventing PICC catheter blockage as described in any one of claims 5 to 7, characterized in that: The gas generating device (4) also includes an electric device (38), which includes an electromagnetic induction coil (39), a power supply (40), and a control circuit (41). A telescopic push rod (42) is provided inside the electromagnetic induction coil (39). The control circuit (41) is used to control the power supply (40) to generate a regular pulse current, and the pulse current is applied to the electromagnetic induction coil (39) so that the telescopic push rod (42) generates a regular reciprocating telescopic motion. The outer end of the telescopic push rod (42) is driven to cooperate with the pressure cap (28) so that the pressure cap (28) is driven to reciprocate through the reciprocating telescopic motion of the telescopic push rod (42).

9. A flushing device for preventing PICC catheter blockage as described in claim 8, characterized in that: Each pulse corresponds to a liquid supply bag (2) to a PICC conduit (9) containing a turbulent fluid with a Reynolds number (Re) greater than 1000.

10. A flushing device for preventing PICC catheter blockage as described in claim 8, characterized in that: The regular pulse current is set to start once every 12 hours, each time containing 6 pulses, each pulse lasting 0.5 seconds, with a 0.5-second interval between two consecutive pulses.

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