A refill device for an intrathecal drug infusion system with filterable venting

Abstract

The present application relates to a kind of reperfusion devices for intrathecal drug infusion system of filterable exhaust, device includes: automatic exhaust valve, filter, syringe, injection needle, needle protection cap, perfusion pipeline, waste liquid discharge pipeline and main body shell;Main body shell integrates exhaust passage, filtration passage, perfusion passage and waste liquid discharge passage, each passage is connected with corresponding component;Automatic exhaust valve includes hydrophobic microporous membrane and elastic reset valve core, when there is gas in passage, gas pressure pushes elastic reset valve core to leave hydrophobic microporous membrane, gas is discharged through the micropore of hydrophobic microporous membrane, when drug liquid contacts hydrophobic microporous membrane, drug liquid cannot pass through micropore, while liquid column pressure compreses elastic reset valve core and tightly adheres to the outside of membrane piece, form mechanical seal.Compared with prior art, the present application integrates filtration, exhaust, perfusion function in single component, simplifies operation process, shortens perfusion time, reduces operation difficulty.

Description

Technical Field

[0001] This invention relates to the field of medical devices, and in particular to a reperfusion device for an intrathecal drug infusion system that can filter exhaust gas. Background Technology

[0002] Targeted Drug Delivery (TDD) is a treatment technique that uses a drug infusion pump implanted in the patient's body to continuously and steadily inject medication into the subarachnoid space. The medication circulates through the cerebrospinal fluid (CSF) and binds to nerve receptors in the spinal cord, thereby treating pain or spasms. According to clinical guidelines, even if the medication has not been completely used up, patients must return to the hospital for reperfusion (i.e., medication change) after 180 days; otherwise, drug crystals and residue can damage the pump motor, causing malfunctions and mechanical failures.

[0003] Traditional intrathecal drug infusion system reperfusion assemblies employ a split-type design, primarily consisting of the following independent components: 1. Infusion tubing and interfaces; 2. Venting device (usually a manual vent valve); 3. Filter (equipped in some systems); 4. Syringe interface.

[0004] The operating procedure is as follows: Medical staff first need to assemble and connect the individual components, inject new medication into the tubing using a syringe, manually open the vent valve to expel gas from the tubing, then connect to the implantable pump for drug infusion, and finally drain and discard the old medication from the pump. This modular design has been used clinically for many years, and related technologies can be found in the product manuals and operating procedures of intrathecal drug infusion systems from companies such as Medtronic.

[0005] Chinese patent CN215084032U discloses a dual-lumen catheter for intrathecal drug infusion, which achieves multi-segment drug infusion through two independent lumens. This invention improves the function of in vivo catheters, but the external reperfusion operation still relies on traditional split-type components. Chinese patent application CN105214200A discloses a catheter for intrathecal drug infusion in humans, which achieves in vivo restraint and leakage prevention by setting an expandable first lumen and a second lumen on the catheter. This technology only improves the catheter body, not the external reperfusion device.

[0006] In summary, existing technologies for improving intrathecal drug infusion systems mainly focus on the structure of the in vivo catheter, fixation methods, and connector protection. However, for the high-frequency, high-risk clinical procedure of reperfusion, the traditional split-type, multi-interface approach is still used, which has prominent problems such as cumbersome operation, high risk of contamination, and significant waste of drug solution. There is an urgent need for an integrated and standardized reperfusion component to solve this problem. Summary of the Invention

[0007] The purpose of this invention is to overcome the defects of the prior art by providing a reperfusion device for an intrathecal drug infusion system that can filter exhaust gas.

[0008] The objective of this invention can be achieved through the following technical solutions: A reperfusion device for an intrathecal drug infusion system with filterable venting capability, the device comprising: an automatic venting valve, a filter, a syringe, an injection needle, a needle cap, a first medical stop clamp, a second medical stop clamp, an infusion line, a waste discharge line, and a main body housing; the main body housing integrates an venting channel, a filtration channel, an infusion channel, and a waste discharge channel; the venting channel is connected to the automatic venting valve; the filtration channel is connected to the filter; the infusion channel is connected to the infusion line; the waste discharge channel is connected to the waste discharge line; the syringe is connected to the filter; the needle cap is fitted onto the injection needle; the end of the injection needle without the needle cap is connected to the infusion line; the first medical stop clamp is fitted onto the infusion line; and the second medical stop clamp is fitted onto the waste discharge line. The automatic exhaust valve includes a hydrophobic microporous membrane and an elastic reset valve core, which are located on the side of the main body housing and fitted between the filter and the filling channel. When there is gas in the channel, the gas pressure pushes the elastic reset valve core away from the hydrophobic microporous membrane, and the gas is discharged through the micropores of the hydrophobic microporous membrane. When the drug solution comes into contact with the hydrophobic microporous membrane, the drug solution cannot pass through the micropores. At the same time, the liquid column pressure compresses the elastic reset valve core to be tightly attached to the outside of the membrane, forming a mechanical seal.

[0009] Furthermore, the infusion channel is located at the front end of the main body shell, the filter channel is located at the rear end of the main body shell, and the exhaust channel and waste liquid discharge channel are located on both sides of the main body shell; the infusion channel is connected to the infusion pipeline through a Luer female connector, and the syringe is connected to the filter through a Luer male connector; the front end of the filter is connected to the filter channel through ultrasonic welding, and the rear end of the filter is connected to the Luer male connector of the syringe through hot melt welding.

[0010] Furthermore, the filter includes a dual-layer filtration membrane structure, an upper filter housing, and a lower filter housing. The dual-layer filtration membrane structure includes a pre-filtration layer and a precision filtration layer. The pre-filtration layer is made of polypropylene meltblown nonwoven fabric that intercepts large-particle drug crystals, rubber debris, and fibrous impurities. The precision filtration layer is made of hydrophilic polyethersulfone asymmetric membrane that blocks bacteria and filters particulate matter. The pre-filtration layer and the precision filtration layer are bonded together by hot-melt welding and placed between the upper filter housing and the lower filter housing.

[0011] Furthermore, the automatic exhaust valve also includes a valve body shell, which is integrally injection molded from medical-grade polypropylene material and seamlessly connected to the main body shell by ultrasonic welding.

[0012] Furthermore, the valve body shell includes an inner gas-liquid contact surface, an outer protective surface, and a membrane fixing groove for fixing a hydrophobic microporous membrane. The inner gas-liquid contact surface is connected to the main body shell and has a circular vent hole with a diameter of 2-3 mm. The outer protective surface is in communication with the external environment and is provided with a waterproof and breathable protective membrane. The hydrophobic microporous membrane is embedded into the membrane fixing groove of the valve body shell by a hot pressing process to form a permanent seal. The hydrophobic microporous membrane is located inside the waterproof and breathable protective membrane.

[0013] Furthermore, the hydrophobic microporous membrane is a hydrophobic polytetrafluoroethylene membrane or a hydrophobically treated polyethersulfone membrane, with a pore size of 0.2-0.45 μm and a thickness of 20-50 μm.

[0014] Furthermore, the injection channel and the waste liquid discharge channel are designed separately inside the main body shell and are respectively connected to the exhaust channel and the filter channel.

[0015] Furthermore, a one-way valve is installed inside the waste liquid discharge channel, which only opens to the outside of the waste liquid flow.

[0016] Furthermore, a raised ring is provided on the waste liquid discharge pipeline, the diameter of which is larger than the diameter of the sleeve hole of the second medical water stop clamp, so that the second medical water stop clamp is clamped at the front end of the waste liquid discharge pipeline.

[0017] Furthermore, a tapered Luer connector is provided at one end of the waste liquid discharge pipeline that discharges waste liquid and is connected to the waste liquid collection pipe.

[0018] Compared with the prior art, the beneficial effects of the present invention include: 1. This invention is an integrated reperfusion device that integrates four core functions—venting, filtering, reperfusion, and waste removal—into a single component. The operation process is simplified to: prepare for connection → discharge old medicine → automatic venting → medicine reperfusion → complete removal. It eliminates the need to complete multiple steps such as component assembly, manual venting, filter connection, and pipeline leak detection in sequence. It requires less operational proficiency from medical personnel and is less prone to errors such as incomplete venting or loose interface connections.

[0019] 2. This invention employs a combination of a hydrophobic microporous membrane and an elastic reset valve core in an automatic exhaust valve. Gas can be automatically discharged in one direction. After the liquid fills the pipeline, the microporous membrane forms a liquid seal, while the elastic valve core adheres tightly to the membrane under the pressure of the liquid column to form a mechanical seal, thus doubly preventing the reverse entry of external air.

[0020] 3. The embedded double-layer filtration structure combined with the valve body shell in this invention achieves three levels of protection: the pre-filtration layer intercepts large particulate impurities such as drug crystals and rubber debris; the precision filtration layer achieves bacterial barrier; and the waterproof and breathable protective membrane prevents the membrane from rupturing under high pressure, ensuring the purity of the infused drug solution.

[0021] 4. This invention adopts a disposable pre-assembled integrated non-removable structure. The integrated design eliminates all intermediate connection interfaces. All functional modules are aseptically packaged during the production process. No assembly operation is required during clinical use, which prevents the possibility of cross-infection during the assembly process.

[0022] 5. The compact design of the integrated pipeline in this invention reduces the residual amount of the total liquid in the pipeline. The automatic exhaust valve only allows gas molecules to pass through, while the liquid cannot pass through the micropores due to surface tension. There is no liquid loss during the exhaust process. The waste liquid channel and the filling channel are designed to be separate within the shell, so the waste discharge process will not contaminate the fresh liquid and avoid drug waste caused by cross-contamination. Attached Figure Description

[0023] Figure 1 This is an overall structural diagram of the re-infusion device of the present invention; Figure 2 This is a schematic diagram showing the usage state of the reperfusion device of the present invention; Figure 3 This is a cross-sectional schematic diagram of the re-infusion device of the present invention; Figure 4 This is a partially enlarged schematic diagram of the automatic exhaust valve in this invention; Figure 5 This is a partially enlarged schematic diagram of the filter in this invention; Figure 6 This is a cross-sectional schematic diagram of the main body shell of the present invention; Figure 7 This is the usage state of the refill device of the present invention during the waste liquid discharge stage; Figure 8 This is the usage status of the reperfusion device of the present invention during the automatic venting and drug perfusion stages; Figure 9 This is a flowchart illustrating the method of using the reperfusion device of the present invention; Figure 10 This is a partial schematic diagram of a waste liquid discharge pipeline with a raised ring in one embodiment of the present invention; Figure 11 This is a schematic diagram of a re-infusion device with a raised ring in one embodiment of the present invention; In the diagram: 11-Automatic air vent valve, 12-Air vent channel, 21-Filter, 22-Filter channel, 3-Injector, 4-Injection needle, 5-Needle cap, 61-First medical stop clamp, 62-Second medical stop clamp, 71-Infusion tubing, 72-Infusion channel, 81-Waste liquid discharge tubing, 82-Waste liquid discharge channel, 9-Main body shell, 10-Protruding ring. Detailed Implementation

[0024] 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, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0025] Example 1 This embodiment discloses a reperfusion device for an intrathecal drug infusion system that can filter exhaust gas, such as... Figure 1 and Figure 3 As shown, the device includes: an automatic exhaust valve 11, a filter 21, a syringe 3, an injection needle 4, a needle protection cap 5, a first medical stop clamp 61, a second medical stop clamp 62, an infusion line 71, a waste liquid discharge line 81, and a main body shell 9. The entire assembly is sterile and disposable.

[0026] Main body shell 9 Figure 6 The device integrates an exhaust channel 12, a filter channel 22, an injection channel 72, and a waste liquid discharge channel 82. The exhaust channel 12 is connected to an automatic exhaust valve 11, the filter channel 22 is connected to a filter 21, the injection channel 72 is connected to an injection pipeline 71, and the waste liquid discharge channel 82 is connected to a waste liquid discharge pipeline 81.

[0027] In another embodiment, in order to prevent waste liquid from mixing with new medicine liquid, the infusion channel 72 and the waste liquid discharge channel 82 are designed to be separated inside the main body shell 9. They are not shown in the figure, but are separated in the form of internal pipes. Each pipe is connected to the exhaust channel 12 and the filter channel 22 respectively.

[0028] The syringe 3 is connected to the filter 21, and the needle protection cap 5 is fitted onto the injection needle 4. The end of the injection needle 4 without the needle protection cap 5 is connected to the infusion tubing 71.

[0029] like Figure 1As shown, the injection needle 4 has an arc of about 12 degrees. This needle with a specific angled bend at the tip is a special curved puncture needle for the reperfusion operation of the intrathecal implantable drug pump. Its curved design is tailored to the anatomical structure of the subcutaneous implanted pump and the pain points of clinical operation. The core purpose is to improve the safety, accuracy and convenience of puncture.

[0030] Automatic exhaust valve 11 Figure 4 As shown, it includes a hydrophobic microporous membrane, an elastic reset valve core, and a valve body shell. The valve body shell is integrally injection molded from medical-grade polypropylene material and seamlessly connected to the main body shell 9 by ultrasonic welding.

[0031] The hydrophobic microporous membrane is a hydrophobic polytetrafluoroethylene membrane or a hydrophobically treated polyethersulfone membrane, with a pore size of 0.2-0.45 μm and a thickness of 20-50 μm.

[0032] Effective breathable area: ≥20mm 2 This ensures that gas can be smoothly discharged when the injection pressure is ≤300kPa.

[0033] The valve body is located on the side of the main housing 9 and is fitted between the filter 21 and the filling channel 72. When there is gas in the channel, the gas pressure pushes the elastic reset valve core away from the hydrophobic microporous membrane. The gas is discharged through the micropores of the hydrophobic microporous membrane. When the drug solution comes into contact with the hydrophobic microporous membrane, the drug solution cannot pass through the micropores. At the same time, the liquid column pressure compresses the elastic reset valve core to stick tightly to the outside of the membrane, forming a mechanical seal.

[0034] The elastic reset valve core is made of medical-grade silicone or thermoplastic elastomer, and has an umbrella-shaped or cylindrical valve core structure with a reset spring at the bottom.

[0035] The valve body shell includes an inner gas-liquid contact surface, an outer protective surface, and a diaphragm fixing groove for fixing a hydrophobic microporous membrane. The inner gas-liquid contact surface is connected to the main body shell 9 and has a circular vent hole with a diameter of 2-3 mm. The outer protective surface is in communication with the external environment and is equipped with a waterproof and breathable protective membrane. The hydrophobic microporous membrane is embedded into the diaphragm fixing groove of the valve body shell through a hot pressing process to form a permanent seal.

[0036] The hydrophobic microporous membrane is located inside the waterproof and breathable protective membrane. The waterproof and breathable protective membrane is made of polypropylene non-woven fabric or PTFE waterproof and breathable membrane with a pore size of 5-10μm. It allows gas to pass through but blocks external liquids and microorganisms. It is fixed to the valve body shell by ultrasonic welding.

[0037] The automatic exhaust valve 11 works as follows: When the syringe injects the medication, the gas in the tubing is pressurized and flows towards the exhaust valve. Due to the hydrophobicity of the microporous membrane, gas molecules can pass through the membrane and escape to the outside, while the medication cannot pass through the micropores due to surface tension, thus achieving gas-liquid separation. When the tubing is filled with medication, the microporous membrane is wetted by the medication to form a liquid seal. At the same time, the elastic valve core adheres tightly to the diaphragm under the pressure of the liquid column and the action of the return spring, forming a double seal, preventing external air from entering the tubing in reverse.

[0038] In another embodiment, the automatic vent valve 11 is fitted at the highest point of the infusion channel (relative to the horizontal operating state) and communicates with the main infusion channel through a lateral branch channel. The vent valve branch channel forms a 45-60° angle with the main body housing 9, ensuring that air bubbles can rise smoothly into the automatic vent valve 11. The connection between the automatic vent valve 11 and the main body housing 9 adopts an arc transition design to avoid dead corners and air bubble residue.

[0039] The injection channel 72 is located at the front end of the main body shell 9, the filter channel 22 is located at the rear end of the main body shell 9, and the exhaust channel 12 and the waste liquid discharge channel 82 are located on both sides of the main body shell 9.

[0040] A first medical stop clamp 61 is fitted onto the infusion pipeline 71, and a second medical stop clamp 62 is fitted onto the waste liquid discharge pipeline 81.

[0041] The infusion channel 72 is connected to the infusion line 71 via a Luer female connector, and the syringe 3 is connected to the filter 21 via a Luer male connector. The front end of the filter 21 is connected to the filter channel 22 via ultrasonic welding, and the rear end of the filter 21 is connected to the Luer male connector of the syringe 3 via hot melt welding.

[0042] Waste liquid discharge pipe 81 is equipped with a tapered Luer connector at one end for connecting to a waste liquid collection pipe. The waste liquid collection pipe can be configured as follows during actual use: Figure 2 The syringe shown.

[0043] The filter 21 is fitted between the automatic exhaust valve 11 and the syringe 3, and adopts a series fitting structure, forming an integrated and non-detachable connection with the automatic exhaust valve 11 and the main body housing 9.

[0044] Filter 21, for example Figure 5 As shown, it includes a dual-layer filter membrane structure, an upper filter housing, and a lower filter housing. The dual-layer filter membrane structure includes a pre-filtration layer and a precision filtration layer.

[0045] The pre-filtration layer is made of polypropylene meltblown nonwoven fabric that intercepts large drug crystals, rubber debris and fibrous impurities. The precision filtration layer is made of hydrophilic polyethersulfone asymmetric membrane that blocks bacteria and filters microparticles. The pre-filtration layer and the precision filtration layer are bonded together by hot-melt welding and placed between the upper and lower housings of the filter.

[0046] The filter housing is made of medical-grade polycarbonate (PC) or polypropylene (PP), and is in the shape of a flat disc or cylinder, with a diameter of 20-30mm and a thickness of 5-8mm. The front end of the filter housing is connected to the housing of the automatic exhaust valve 11 by ultrasonic welding, and the rear end is connected to the interface end of the syringe 3 by hot melt welding.

[0047] Specifically, the pre-filter layer has a pore size of 5μm, a thickness of 0.5-1mm, and a filtration area of ​​≥100mm². 2 .

[0048] The precision filter layer has a pore size of 0.2μm (absolute pore size), a thickness of 100-150μm, and a filtration area of ​​≥50. .

[0049] Outside the precision filter layer, there is also a polyester fiber non-woven fabric support layer with a thickness of 0.3mm to prevent the membrane from breaking under high pressure.

[0050] The diaphragm is fixed and fitted using a composite process combining thermofusion welding and ultrasonic welding. The fitting process includes: Two layers of filter membrane are bonded together into one piece by hot-melt welding (temperature 120-150℃); The composite membrane is placed between the upper and lower housings of the filter housing; The upper and lower shells are sealed by ultrasonic welding, while the edges of the diaphragm are firmly clamped. After welding, the diaphragm has uniform tension and is free of wrinkles and damage.

[0051] The outer edges of the automatic exhaust valve 11 and the filter 21 are ultrasonically welded to form an annular weld with a weld width ≥2mm to ensure connection strength and sealing.

[0052] The specific operating procedure of this device is as follows: Figure 9 As shown, it includes: Step S1: Preparation Phase Remove the component packaging, connect the front Luer female connector to the drug pump injection needle, and the rear connector to the drug syringe and waste liquid collector. The overall assembly is as follows: Figure 2 As shown.

[0053] Step S2: Draining stale medicine The pump draws back the old medicine solution inside, which then flows through the waste liquid channel into the waste liquid collector to complete the emptying process. The medical stop clamp is then closed to shut off the waste liquid return channel.

[0054] The re-injection device in this step is as follows: Figure 7 As shown, when the syringe is pulled back along the direction of the black arrow, the waste liquid in the drug pump flows back into the waste liquid channel along the direction of the red arrow.

[0055] Step S3: Automatic exhaust Using a medication syringe (filled with fresh medication), along as... Figure 8 As shown by the black arrow, the gas is slowly injected along the direction indicated. Figure 8 The air is automatically discharged through the exhaust valve, as indicated by the blue arrow.

[0056] Step S4: Drug infusion Continue injecting the syringe, the medication as... Figure 8 The yellow arrow indicates that the drug enters the pump after being filtered, with an injection rate of 2-5 mL / min and a total infusion time of 3-5 minutes.

[0057] Step S5: Complete the removal After the infusion is complete, unscrew all the interfaces and discard the entire component; no disassembly and cleaning are required.

[0058] Example 2 This embodiment, based on the above embodiment, discloses a reperfusion device for an intrathecal drug infusion system with filterable exhaust gas, capable of preventing waste liquid backflow. The device differs from the device disclosed in Embodiment 1 in that, as... Figure 10 and Figure 11 As shown, a raised ring 10 is provided on the waste liquid discharge pipe 81.

[0059] Traditional waste fluid tubing consists of smooth, straight pipes, allowing the medical stop clamp to slide freely within the tubing. During clinical procedures, medical staff often clamp the stop clamp at the distal end, close to the waste fluid collection bag, due to habit or obstructed vision. In this case, a 5-10cm section of stale waste fluid remains between the clamping point and the bifurcation between the infusion and waste fluid channels. When fresh medication is injected, the pressure within the infusion channel forces this residual waste fluid back into the drug pump reservoir, contaminating the fresh medication, reducing drug concentration, and affecting treatment efficacy.

[0060] The diameter of the raised ring 10 is slightly larger than the diameter of the circular fitting hole of the second medical water-stop clamp 62, which is used to clamp the second medical water-stop clamp 62 at the front end of the waste liquid discharge pipe 81. When the water-stop clamp slides along the pipe toward the bifurcation, it will be blocked by the raised ring 10 and cannot move forward, thus forcibly fixing the clamping point at the position closest to the bifurcation.

[0061] Example 3 This embodiment, based on the above embodiment, discloses a reperfusion device for an intrathecal drug infusion system with filterable exhaust gas, capable of preventing waste liquid backflow. The device differs from the device disclosed in Embodiment 1 in that a one-way valve is provided inside the waste liquid discharge channel 82, and the one-way valve only opens to the outside of the waste liquid outflow. Figure 6 (Drawn in the middle).

[0062] The one-way valve adopts a medical-grade silicone duckbill or umbrella-shaped structure, which only allows waste liquid to flow in one direction from the waste liquid discharge channel 82 port to the waste liquid collection bag. Under reverse pressure, it automatically forms a zero-leakage seal.

[0063] When aspirating old medication, if medical staff accidentally release the syringe plunger, a momentary negative pressure will be generated in the tubing, drawing the air and discharged waste fluid from the waste bag back into the pump. The one-way valve will immediately close under the negative pressure, completely preventing this momentary backflow and ensuring that the aspirated waste fluid does not re-enter the patient's body.

[0064] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A reperfusion device for an intrathecal drug infusion system with filterable exhaust gas, characterized in that, The device includes: an automatic vent valve (11), a filter (21), a syringe (3), an injection needle (4), a needle protective cap (5), a first medical stop clamp (61), a second medical stop clamp (62), an infusion line (71), a waste liquid discharge line (81), and a main body housing (9); the main body housing (9) integrates an vent channel (12), a filter channel (22), an infusion channel (72), and a waste liquid discharge channel (82), the vent channel (12) being connected to the automatic vent valve (11), and the filter channel (22) being connected to the filter. The filter (21) is connected, the infusion channel (72) is connected to the infusion line (71), the waste liquid discharge channel (82) is connected to the waste liquid discharge line (81), the syringe (3) is connected to the filter (21), the needle protection cap (5) is fitted on the injection needle (4), the end of the injection needle (4) without the needle protection cap (5) is connected to the infusion line (71), the first medical stop clamp (61) is fitted on the infusion line (71), and the second medical stop clamp (62) is fitted on the waste liquid discharge line (81). The automatic exhaust valve (11) includes a hydrophobic microporous membrane and an elastic reset valve core, which are located on the side of the main body housing (9) and fitted between the filter (21) and the infusion channel (72). When there is gas in the channel, the gas pressure pushes the elastic reset valve core away from the hydrophobic microporous membrane, and the gas is discharged through the micropores of the hydrophobic microporous membrane. When the liquid medicine comes into contact with the hydrophobic microporous membrane, the liquid medicine cannot pass through the micropores. At the same time, the liquid column pressure compresses the elastic reset valve core to stick tightly to the outside of the membrane, forming a mechanical seal.

2. The reperfusion device for an intrathecal drug infusion system with filterable exhaust gas according to claim 1, characterized in that, The infusion channel (72) is located at the front end of the main body shell (9), the filter channel (22) is located at the rear end of the main body shell (9), and the exhaust channel (12) and waste liquid discharge channel (82) are located on both sides of the main body shell (9). The infusion channel (72) is connected to the infusion pipeline (71) through a Luer female connector, and the syringe (3) is connected to the filter (21) through a Luer male connector. The front end of the filter (21) is connected to the filter channel (22) through ultrasonic welding, and the rear end of the filter (21) is connected to the Luer male connector of the syringe (3) through hot melt welding.

3. A reperfusion device for an intrathecal drug infusion system with filterable exhaust gas according to claim 1, characterized in that, The filter (21) includes a double-layer filter membrane structure, an upper filter housing, and a lower filter housing. The double-layer filter membrane structure includes a pre-filter layer and a precision filter layer. The pre-filter layer is made of polypropylene meltblown nonwoven fabric that intercepts large-particle drug crystals, rubber debris, and fibrous impurities. The precision filter layer is made of hydrophilic polyethersulfone asymmetric membrane that blocks bacteria and filters microparticles. The pre-filter layer and the precision filter layer are combined into one piece by hot-melt welding and placed between the upper filter housing and the lower filter housing.

4. A reperfusion device for an intrathecal drug infusion system with filterable exhaust gas according to claim 1, characterized in that, The automatic exhaust valve (11) also includes a valve body shell, which is integrally injection molded from medical-grade polypropylene material and seamlessly connected to the main body shell (9) by ultrasonic welding.

5. A reperfusion device for an intrathecal drug infusion system with filterable exhaust gas according to claim 4, characterized in that, The valve body shell includes an inner gas-liquid contact surface, an outer protective surface, and a membrane fixing groove for fixing a hydrophobic microporous membrane. The inner gas-liquid contact surface is connected to the main body shell (9) and has a circular exhaust hole with a diameter of 2-3 mm. The outer protective surface is in communication with the external environment and is provided with a waterproof and breathable protective membrane. The hydrophobic microporous membrane is embedded into the membrane fixing groove of the valve body shell by a hot pressing process to form a permanent seal. The hydrophobic microporous membrane is located inside the waterproof and breathable protective membrane.

6. A reperfusion device for an intrathecal drug infusion system with filterable exhaust gas according to claim 1, characterized in that, The hydrophobic microporous membrane is a hydrophobic polytetrafluoroethylene membrane or a hydrophobically treated polyethersulfone membrane, with a pore size of 0.2-0.45 μm and a thickness of 20-50 μm.

7. A reperfusion device for an intrathecal drug infusion system with filterable exhaust gas according to claim 1, characterized in that, The filling channel (72) and the waste liquid discharge channel (82) are designed separately inside the main body shell (9) and are respectively connected to the exhaust channel (12) and the filter channel (22).

8. A reperfusion device for an intrathecal drug infusion system with filterable exhaust gas according to claim 1, characterized in that, The waste liquid discharge channel (82) is equipped with a one-way valve, which only opens to the outside of the waste liquid discharge channel.

9. A reperfusion device for an intrathecal drug infusion system with filterable exhaust gas according to claim 1, characterized in that, A raised ring (10) is provided on the waste liquid discharge pipeline (81). The diameter of the raised ring (10) is larger than the diameter of the sleeve hole of the second medical water stop clamp (62). The second medical water stop clamp (62) is clamped at the front end of the waste liquid discharge pipeline (81).

10. A reperfusion device for an intrathecal drug infusion system with filterable exhaust gas according to claim 1, characterized in that, The waste liquid discharge pipeline (81) is provided with a tapered Luer connector at one end that is connected to the waste liquid collection pipe.

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