System for evaluating blood filter

Abstract

The utility model discloses a system for evaluating a blood filter, which comprises a blood delivery passage, a blood filter, a blood sampling device, a blood sampling device, a blood filter and a blood filter, and is characterized in that the blood delivery passage is provided with a sampling port and an anticoagulant infusion bypass; a blood return passage; the filtrate bypass is provided with a filtrate suction bypass for sucking filtrate; the liquid storage cavity is divided into a first cavity and a second cavity through a separation structure, at least part of the separation structure is of a soft film structure, and the soft film structure can deform along the pressure difference of the two sides so that the cavity on the side with the large pressure can be enlarged, and the cavity on the side with the small pressure can be shrunk; an inlet of the anticoagulant infusion bypass is communicated with the first chamber, and an outlet of the filtrate suction bypass is communicated to the second chamber; at least one of the anticoagulant infusion bypass and the filtrate suction bypass is provided with a fluid pump. The system for evaluating the use time of the hemofilter can effectively solve the problem that the balance effect of infusing anticoagulant and extracting filtrate is poor.

Description

Technical Field

[0001] The utility model relates to the technical field of medical treatment, and more particularly to a system for evaluating the use time of a blood filter. Background Art

[0002] Continuous renal replacement therapy (CRRT) is a blood purification method that slowly and continuously removes cytotoxins, metabolic waste products, and inflammatory factors from the patient's body, improving tissue oxygen metabolism and maintaining acid-base and electrolyte balance. It offers advantages such as stable hemodynamics and high solute clearance. To maximize efficacy, CRRT should operate 24 hours a day or provide a prescribed clearance rate. During treatment, problems with membrane materials or intravenous clotting often occur, potentially leading to treatment interruptions and the need for urgent filter replacement. This not only increases circuit and filter costs and healthcare staff workload, but also places patients at risk of blood loss and infection. Therefore, the lifespan of a hemofilter is a crucial fundamental performance indicator. Due to patient variability in blood parameters and coagulation markers at the start of treatment, such as platelet count, neutrophil count, activated partial thromboplastin time, prothrombin time, and fibrinogen, as well as variations in these markers during treatment, assessing the lifespan of a hemofilter in clinical settings is difficult. This requires an in vitro system that can evaluate basic performance criteria of hemofilters, such as solute removal performance, usage time, and antithrombotic properties, under stable conditions, to provide reliable information for developing or modifying membrane materials.

[0003] Current technology for evaluating the lifespan of hemofilters primarily relies on a hemofiltration experiment conducted under conditions simulating clinical blood flow and pressure. Anticoagulant-treated fresh blood is introduced into a closed-loop system for circulation. A resistance-applying device is installed on one side of the venous access to simulate human venous pressure, and a starting pre-filtration pressure similar to clinical conditions is set. Hemofiltration is then performed after adjusting blood flow and filtrate flow rates to those similar to clinical conditions. The time it takes to reach the target pre-filtration pressure is considered the filter's lifespan.

[0004] The inventors have found through long-term practice that some systems for evaluating blood filters have a problem of poor balance between infusing anticoagulants and extracting filtrate. Utility Model Content

[0005] In view of this, the purpose of the present invention is to provide a system for evaluating a blood filter, which can effectively solve the problem of poor balance between infusing anticoagulants and extracting filtrate.

[0006] In order to achieve the above-mentioned purpose, the present invention provides the following technical solutions:

[0007] A system for evaluating a hemofilter, comprising:

[0008] A blood supply passage, the outlet of which is connected to the blood chamber inlet of the blood filter, and the blood supply passage is provided with a sampling port and an anticoagulant infusion bypass;

[0009] A blood return passage, the inlet of which is used to communicate with the blood chamber outlet of the blood filter;

[0010] a filtrate bypass, wherein the inlet of the filtrate bypass is used to communicate with the filtrate outlet of the hemofilter, and the filtrate bypass has a filtrate suction bypass for sucking the filtrate;

[0011] A liquid storage chamber, the liquid storage chamber is divided into a first chamber and a second chamber by a partition structure, the partition structure is at least partially a soft membrane structure, and the soft membrane structure can deform along the pressure difference on both sides to expand the chamber on the side with higher pressure and shrink the chamber on the side with lower pressure; the inlet of the anticoagulant infusion bypass is connected to the first chamber, and the outlet of the filtrate suction bypass is connected to the second chamber; at least one of the anticoagulant infusion bypass and the filtrate suction bypass is provided with a fluid pump.

[0012] In the aforementioned system for evaluating the lifespan of a hemofilter, during use, the hemofilter is installed at the corresponding interface, and the entire system is then activated, such as by activating the fluid pumps therein or by changing the positional relationship to allow internal blood circulation. During this process, either the fluid pump in the anticoagulant infusion bypass or the fluid pump in the filtrate suction bypass is activated. Regardless of which is activated, due to the presence of the soft membrane structure, anticoagulant in the first chamber is introduced through the anticoagulant infusion bypass, simulating the human coagulation environment. Simultaneously, a volume of filtrate equal to the injected anticoagulant solution is discharged through the filtrate suction bypass, thereby balancing the overall circuit fluid content and better simulating the human body's usage environment. In the above-mentioned system for evaluating a blood filter, because a liquid storage chamber is provided, and two chambers, namely a first chamber and a second chamber, are correspondingly separated by a soft membrane structure, whether the fluid pump in the anticoagulant infusion bypass is started or the fluid pump in the filtrate suction bypass is started, when the soft membrane structure deforms along the pressure difference, the first chamber will inevitably become smaller, which will inevitably cause the second chamber to increase, and the increase and decrease in volume are balanced. In addition, the structure is simple, which can better ensure that the volume of the aspirated solution and the volume of the infused solution are equal, or nearly equal, to better ensure the balance of the entire system. In summary, the system for evaluating the use time of a blood filter can effectively solve the problem of poor balance between infusing anticoagulants and extracting filtrate.

[0013] In some technical solutions, the soft membrane structure is constructed as a bag-type structure, and the bag-type structure is arranged in the liquid storage cavity; one of the first chamber and the second chamber is the inner cavity of the bag-type structure, and the other is the chamber between the wall of the liquid storage cavity and the bag-type structure.

[0014] In some technical solutions, the inner cavity of the bag-type structure is the second chamber, and the cavity between the bag-type structure and the wall of the liquid storage chamber is the first chamber.

[0015] In some technical solutions, the liquid storage container includes a glass bottle, and the bag-type structure is located in the glass bottle cavity; the filtrate suction bypass passes through the bottle mouth plug of the glass bottle to be inserted into the bag mouth of the bag-type structure, and a drainage opening is provided on the side wall of the glass bottle to connect to the inlet of the anticoagulant infusion bypass.

[0016] In some technical solutions, the glass bottle is a conical bottle, and the drainage opening is arranged at the bottom of the glass bottle.

[0017] In some technical solutions, a closable connecting tube is provided at the bottle mouth of the glass bottle to connect with the glass bottle cavity.

[0018] In some technical solutions, an internal pressure regulating device is further included, the outlet of which is connected to the inlet of the blood supply passage, and the inlet is connected to both the outlet of the blood return passage and the outlet of the filtrate bypass.

[0019] In some technical solutions, a blood pump is provided on the blood supply passage, and the sampling port and the inlet of the anticoagulant infusion bypass are both connected between the outlet of the blood supply passage and the blood pump.

[0020] In some technical solutions, a resistance applying device, a venous pressure gauge and a venous simulation elastic tube are sequentially arranged on the blood return path along the fluid direction.

[0021] In some technical solutions, a heating device is also included; the blood delivery pathway is provided with the blood delivery pump, the sampling port, the arterial pot and the pre-filtration pressure gauge along the blood delivery direction; the inlet of the anticoagulant infusion bypass is connected between the sampling port and the arterial pot; the venous pressure gauge, the venous simulation elastic tube and the internal pressure regulating device are all provided in the heating area of ​​the heating device; the anticoagulant infusion bypass and the filtrate suction bypass are both provided with the fluid pump; and the filtrate bypass is provided with a filtrate pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 This is a schematic diagram of the structure of a system for evaluating the usage time of a blood filter provided by an embodiment of the present utility model.

[0024] The following are marked in the accompanying drawings:

[0025] 1-blood filter; 1a-blood chamber inlet; 1b-blood chamber outlet; 1c-filtrate outlet; 1e-hollow fiber membrane; 2-blood supply passage; 3-blood return passage; 4-filtrate bypass; 5-anticoagulant infusion bypass; 6-filtrate suction bypass; 7-blood supply pump; 8-filtrate pump; 9-fluid pump; 10-glass bottle; 11-soft membrane structure; 12-resistance applying device; 13-venous simulation elastic tube; 14-internal pressure regulating device; 15-arterial pot; 16-pre-filtration pressure gauge; 17-venous pressure gauge; 18-sampling port; 19-heating device. DETAILED DESCRIPTION

[0026] The embodiment of the utility model discloses a system for evaluating a blood filter, which effectively solves the problem of poor balance between infusing anticoagulants and extracting filtrate.

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0028] See also Figure 1 , Figure 1 This is a schematic diagram of the structure of a system for evaluating the usage time of a blood filter provided by an embodiment of the present utility model.

[0029] In some embodiments, a system for evaluating a hemofilter 1 is provided. This system can be used to evaluate the lifespan of the hemofilter and thereby test the lifespan of the hemofilter 1. Specifically, the system for evaluating the hemofilter 1 primarily includes a blood supply path 2, a blood return path 3, a filtrate bypass 4, and a liquid storage chamber. It may also typically include an internal pressure regulating device 14. It should be noted that the path can be a pipeline, a channel within an integrated block, or a combination of both.

[0030] During use, the blood supply path 2, blood filter 1, and blood return path 3 need to be sequentially connected in a circular fashion. Other devices may be installed between adjacent paths to provide indirect communication. When an internal pressure regulating device 14 is provided, it is positioned between the outlet of the blood return path 3 and the inlet of the blood supply path 2, participating in the circular communication. The blood supply path 2, blood return path 3, and internal pressure regulating device 14 are all used to simulate the internal environment of the human body. The blood filter 1 is typically provided with a hollow fiber membrane 1d.

[0031] Blood supply channel 2 delivers blood to the blood chamber inlet 1a of hemofilter 1. Hemofilter 1 performs filtration, and the filtered fluid, called filtrate, flows out of filtrate outlet 1c. The remaining portion, called return blood, flows out of blood chamber outlet 1b and enters return blood channel 3. It then passes through the venous elastic tube and the internal pressure regulating device before returning to blood supply channel 2. The filtrate flowing out of filtrate outlet 1c is then channeled out through filtrate bypass 4. Generally speaking, filtrate bypass 4 allows filtrate to bypass hemofilter 1 and return to the main system through the inlet of the internal pressure regulating device 14, simulating the continuous production of toxins in the human body.

[0032] The outlet of the blood supply passage 2 is connected to the blood chamber inlet 1a of the blood filter 1, and a sampling port 18 and an anticoagulant infusion bypass 5 are provided on the blood supply passage 2. Anticoagulant is introduced into the blood supply passage 2 through the anticoagulant infusion bypass 5, either periodically or continuously, generally by injection through a pump. The sampling port 18 allows for regular sampling, allowing for analysis of the activated coagulation detection time. The activated coagulation detection time can be used to control the amount of anticoagulant introduced into the anticoagulant infusion bypass 5 to better simulate human use.

[0033] The inlet of the filtrate bypass 4 is used to connect to the filtrate outlet 1c of the blood filter 1. At the same time, the filtrate bypass 4 has a filtrate suction bypass 6 for sucking the filtrate. The filtrate suction bypass 6 is provided on the filtrate bypass 4 so that a portion of the filtrate can be correspondingly extracted. The filtrate generally does not contain blood, but contains water, electrolytes, proteins, coagulation factors, etc., which are solutions with the same properties as the injected anticoagulant solution but different components, so that the volume, solution osmotic pressure and other effects brought by the injection of the anticoagulant can be balanced.

[0034] The liquid storage chamber is generally formed in a container. The liquid storage chamber is divided into a first chamber and a second chamber by a partition structure. The inlet of the anticoagulant infusion bypass 5 is connected to the first chamber, so that during use, anticoagulant can be injected into the first chamber, and then the anticoagulant flows from the first chamber to the anticoagulant infusion bypass 5 and into the blood supply channel 2. The outlet of the filtrate suction bypass 6 is connected to the second chamber, so that filtrate extracted from the filtrate suction bypass 6 can be discharged into the second chamber.

[0035] The partition structure is at least partially constructed of a flexible membrane structure 11. This membrane structure 11 can deform in response to the pressure differential between the two sides, expanding the chamber on the side with higher pressure and shrinking the chamber on the side with lower pressure. Pressure can be measured by hydraulic pressure or air pressure. For example, when the first chamber discharges anticoagulant, the second chamber is forced to admit filtrate. Conversely, when the second chamber is pumped with filtrate, the pressure on the first chamber forces the anticoagulant out.

[0036] Furthermore, at least one of the anticoagulant infusion bypass 5 and the filtrate suction bypass 6 is provided with a fluid pump 9 to actively infuse the anticoagulant and / or suction the filtrate, thereby actively reducing the pressure in the first chamber and / or actively increasing the pressure in the second chamber, thereby completing infusion and suction of the entire liquid storage cavity. It should be noted that, generally speaking, to complete infusion and suction of the entire liquid storage cavity, only one of the anticoagulant infusion bypass 5 and the filtrate suction bypass 6 may be provided with a fluid pump 9, or both may be provided with a fluid pump 9.

[0037] In actual application, the soft membrane structure 11 makes it possible that when in use: when the anticoagulant infusion bypass 5 is provided with a fluid pump 9, under the action of the fluid pump 9, the first chamber is forced to supply anticoagulant into the anticoagulant infusion bypass 5. At this time, the pressure of the first chamber will decrease, causing the pressure of the second chamber to increase relatively. Then, the soft membrane structure 11 will deform toward the first chamber to increase the volume of the second chamber and reduce the volume of the corresponding first chamber. Because the volume of the second chamber increases, the current pressure of the second chamber is higher than its previous pressure. It will decrease, and at this time, a suction effect will be generated on the filtrate suction bypass 6. When the filtrate sucked by the filtrate suction bypass 6 is input into the second chamber, the pressure in the second chamber will increase to form a new balance; when the filtrate suction bypass 6 is provided with a fluid pump 9, under the action of the fluid pump 9, the filtrate is forced to enter the second chamber, the pressure in the second chamber increases, and the soft membrane structure 11 is squeezed, so that the volume of the first chamber becomes smaller, and the pressure in the first chamber becomes larger, so that the internal anticoagulant is output and enters the anticoagulant infusion bypass 5 to complete the infusion.

[0038] In the aforementioned system for evaluating the usage time of a hemofilter 1, during use, the hemofilter 1 is installed at the corresponding interface, and the entire system is then activated, such as by activating the fluid pump 9 therein or changing the positional relationship to allow internal blood circulation. During this process, either the anticoagulant infusion bypass 5 or the fluid pump 9 in the filtrate suction bypass 6 is activated. Regardless of which is activated, due to the presence of the soft membrane structure 11, the anticoagulant in the first chamber is introduced through the anticoagulant infusion bypass 5, simulating the human coagulation environment. Simultaneously, a volume of filtrate equal to the injected anticoagulant solution is discharged through the filtrate suction bypass 6, thereby balancing the overall circuit liquid content and better simulating the human usage environment. In the above-mentioned system for evaluating the blood filter 1, because a liquid storage chamber is provided and two chambers, namely a first chamber and a second chamber, are separated by a soft membrane structure 11, whether the fluid pump 9 in the anticoagulant infusion bypass 5 or the fluid pump 9 in the filtrate suction bypass 6 is started, when the soft membrane structure 11 deforms along the pressure difference, the first chamber will become smaller, which will inevitably cause the second chamber to increase. The increase and decrease in volume are balanced, and the structure is simple, which can better ensure that the volume of the aspirated solution and the volume of the infused solution are equal, or nearly equal, to better ensure the balance of the entire system. In summary, the system for evaluating the service life of the blood filter 1 can effectively solve the problem of poor balance between infusing anticoagulants and extracting filtrate.

[0039] In some instances, the soft membrane structure 11 can be made into a sheet shape, with its edges forming a sealing fit with the wall of the liquid storage chamber to laterally separate the liquid storage chamber into a first chamber and a second chamber. This separation cannot ensure that the pressure of the two chambers is balanced in time.

[0040] Based on this, the soft film structure 11 is preferably constructed as a bag-type structure, which is disposed within the liquid storage cavity. One of the first and second chambers is the inner cavity of the bag-type structure, and the other is the chamber between the liquid storage cavity and the bag-type structure. The provision of a bag-type structure can better ensure volume changes in the bag-type structure, thereby better balancing pressure between the first and second chambers, preventing the bag-type structure from being subjected to excessive tension, and thus better balancing the volume of the aspirated solution and the volume of the infused solution. Specifically, the bag-type structure can be an infusion bag or other structures.

[0041] In some embodiments, the inner cavity of the bag-shaped structure is the second chamber, and the cavity between the bag-shaped structure and the wall of the liquid storage chamber is the first chamber. Generally speaking, in practical applications, the anticoagulant is usually directly placed in the soft bag and then directly placed in the liquid storage chamber when in use.

[0042] In this case, the liquid storage container can be a glass bottle 10, and the bag-shaped structure can be inserted into the glass bottle 10 from the bottle mouth. The filtrate suction bypass 6 can then be inserted through the bottle mouth plug of the glass bottle 10 and into the bag mouth of the bag-shaped structure. The bottle mouth generally faces upward, and the bag mouth of the bag-shaped structure also generally faces upward.

[0043] In some embodiments, to facilitate the input of anticoagulant between the glass bottle 10 and the bag-type structure into the anticoagulant infusion bypass 5, a drainage opening can be provided on the side wall of the glass bottle 10 to connect to the inlet of the anticoagulant infusion bypass 5. Specifically, a tube can be extended from the bottom to serve as the drainage opening to facilitate connection to the anticoagulant infusion bypass 5.

[0044] In some embodiments, the bottle body used in the liquid storage container can be a glass bottle 10, or a plastic bottle or a ceramic bottle, etc. The bottle body used in the liquid storage container can be a square bottle, a cylindrical bottle or a bottle body of other shapes.

[0045] In some embodiments, the preferred liquid storage container is a conical flask, with the cross-sectional area of ​​the inner cavity gradually increasing from top to bottom. This is because, during use, the bottom of a bag-type structure generally swells first as the filtrate enters. Using a conical flask can better prevent the bag-type structure from blocking the drainage opening, thereby ensuring the drainage of the anticoagulant. In this case, the drainage opening can be correspondingly located at the bottom of the glass bottle 10 to better drain the anticoagulant.

[0046] In some embodiments, in order to better input the anticoagulant, it is preferred that a closable connecting tube is provided at the mouth of the glass bottle 10 to connect to the inner cavity of the glass bottle 10. Instead of injecting from the bottle mouth, this facilitates the stable input of anticoagulant through the connecting tube when the bottle mouth is closed, so as to actively balance the entire system.

[0047] In some embodiments, an internal pressure balancing device may be provided, wherein the outlet of the internal pressure regulating device 14 is connected to the inlet of the blood supply passage 2, and the inlet is connected to the outlet of the return blood passage 3 and the outlet of the filtrate bypass 4, so as to obtain the returned blood and filtrate at the same time. Because sampling through the sampling port may cause the osmotic pressure of the internal solution to decrease, an equal volume of normal saline may be injected into the internal pressure regulating device 14 while sampling, so as to balance the negative pressure generated by the system during sampling. Specifically, a normal saline infusion device may be provided at the internal pressure regulating device 14. The internal pressure regulating device 14 may be a rectangular device with an elastic tube connected inside and normal saline filled outside the tube.

[0048] In some embodiments, a filtrate pump 8 is provided on the filtrate bypass 4, and the inlet of the filtrate suction bypass 6 is connected between the filtrate pump 8 and the outlet of the filtrate bypass 4. When the inlet of the filtrate suction bypass 6 is provided at the outlet of the filtrate pump 8, the fluid pressure obtained is more stable, which facilitates the control of the extraction speed and more accurately balances the entire blood system.

[0049] In some embodiments, a blood pump 7 is provided on the blood supply passage 2, and the sampling port 18 and the inlet of the anticoagulant infusion bypass 5 are both connected between the outlet of the blood supply passage 2 and the blood pump 7. Compared with the inlet of the blood pump 7, the fluid pressure at the outlet of the blood pump 7 is more stable. Therefore, providing the outlet of the blood pump 7 here can ensure a better sampling capacity and anticoagulant injection speed.

[0050] In some embodiments, the blood return path 3 is sequentially provided with one, more, or all of the following: a resistance applying device 12, a venous pressure gauge 17, and a venous simulation elastic tube 13. The resistance applying component, which applies resistance to the blood return path 3, may be a clamp or a valve. The venous elastic tube, used to simulate venous pressure close to that of the human body, may be a silicone tube or a polyurethane tube. The venous pressure gauge 17 is used to measure and obtain venous fluid pressure.

[0051] In some embodiments, the blood supply passage 2 is provided with the blood supply pump 7, the sampling port 18, the arterial pot 15, and the pre-filtration pressure gauge 16 along the blood supply direction. The arterial pot 15 is used to store a portion of blood to ensure the blood volume. The pre-filtration pressure gauge 16 is used to measure the pre-filtration fluid pressure. This facilitates the analysis of the usage status of the blood filter 1 by obtaining the pressure. The pre-filtration pressure gauge 16 and the venous pressure gauge 17 are both diaphragm pressure measuring devices that are not in contact with air and monitor the pre-filtration pressure and venous pressure, respectively.

[0052] In some embodiments, specifically, the inlet of the anticoagulant infusion bypass 5 can be connected between the sampling port 18 and the arterial pot 15 to ensure better mixing of the anticoagulant.

[0053] In some embodiments, a heating device 19 is further included, and the venous pressure gauge 17, the vein simulation elastic tube 13, and the internal pressure regulating device 14 are all disposed within the heating area of ​​the heating device 19. The heating device 19 is used to maintain a constant temperature of the simulated vein passage at 37°C. The heating device 19 can be a water bath or other constant temperature heating device 19.

[0054] In some embodiments, the system for evaluating a blood filter includes: a blood filter 1, a blood supply passage 2, a blood return passage 3, a filtrate bypass 4, an anticoagulant infusion bypass 5, a filtrate suction bypass 6, an anticoagulant infusion pump 9, a filtration bottle 10, a waste liquid bag 11, an arterial pot 15, a pre-filtration pressure gauge 16, a venous pressure gauge 17, a sampling port 18, and a heating device 19.

[0055] The blood supply passage 2 is used to deliver blood to the hemofilter 1 via the blood supply pump 7 .

[0056] The blood return path 3 transports the blood flowing out of the blood filter 1 to the vein-simulating elastic tube 13 and the internal pressure regulating device 14 via the resistance applying device 12 .

[0057] The resistance applying component 12 is a device that can apply resistance to the blood return path, and can be a clamp or a valve.

[0058] The vein simulation elastic tube 13 is used to simulate venous pressure close to that of the human body and can be a silicone tube or a polyurethane tube.

[0059] The internal pressure regulating device 14 is a rectangular device made of acrylic material, with an elastic tube connected inside and filled with physiological saline.

[0060] The filtrate bypass 4 delivers the ultrafiltrated liquid from the hemofilter 1 to the blood return path 3 via the filtrate pump 8 .

[0061] The arterial cuff 15 is used to store a portion of blood.

[0062] The pre-filtration pressure gauge 16 and the venous pressure gauge 17 are both diaphragm pressure measuring devices that are not in contact with air and monitor the pre-filtration pressure and venous pressure respectively.

[0063] The sampling port 18 is used to collect blood samples for monitoring the activated clotting time.

[0064] The heating device 19 is used to keep the temperature of the simulated vein passage constant at 37° C. and can be a water bath or other constant temperature heating device.

[0065] The hemofiltration operation is completed by driving the blood delivery pump 7 and the filtrate pump 8. Driven by the fluid pump 9, the anticoagulant enters the circulating blood circuit for blood anticoagulation. Simultaneously, an equal amount of filtrate is introduced from the filtrate bypass 4 via the filtrate suction bypass 6 into the bag-type structure. This ensures continuous infusion of anticoagulant under simulated clinical conditions while maintaining a constant total volume in the circulating blood circuit, making the evaluation of the hemofilter's service life more simple and accurate. After the in vitro hemofiltration experiment begins, a resistance-applying component 12 applies a certain resistance to the return blood path 3 to simulate human venous pressure. At regular intervals, blood samples are collected from the sampling port 18. The heparin infusion rate is adjusted by monitoring the activated clotting time to simulate the actual anticoagulation environment in clinical practice. Simultaneously with sampling, an equal volume of saline is injected into the internal pressure regulating device to balance the negative pressure generated by the sampling. A pre-filtration pressure of 150 mmHg (millimeters of mercury) is used as the threshold, and the time when this pressure value is reached is considered the filter's service life.

[0066] The blood filtration process is as follows:

[0067] The glass bottle is filled with anticoagulant solution in advance, and the air in the bag structure is exhausted. It is then connected to the circulating blood circuit through the anticoagulant infusion line 5 and the filtrate suction line 6. After the blood filter is fully pre-flushed, blood is filled into the blood supply line 2 and the blood return line 3 as the test liquid. The blood supply pump 7 and the filtrate pump 8 are driven to start the blood filtration mode. Figure 1 As indicated by the arrow in the middle, filtrate, driven by pump 8, flows from outlet 1c on one side of the hemofilter 1 into the filtrate bypass 4 and ultimately into the blood return line 3, achieving filtrate recirculation. To simulate the actual anticoagulant environment in clinical practice, fluid pump 9 is driven to cause anticoagulant to flow from the anticoagulant infusion line 5 to the blood delivery line 2. Simultaneously, under pressure, an equal volume of filtrate is drawn from the filtrate bypass 4 into the filtrate aspiration line 6, ultimately flowing into the bag-type structure. To simulate human vascular resistance, a resistance application device 11 is installed in the blood return line 3 to adjust the initial pre-filtration pressure to 70 mmHg. The initial venous pressure is also adjusted to 7 mmHg by adjusting the height of the venous elastic tubing.

[0068] The coagulation monitoring process is as follows:

[0069] During the hemofiltration process, blood samples are collected from sampling port 18 at intervals of 0, 1, 3, 6, 12, 24, 36, and 48 hours to test the activated clotting time. To test the activated clotting time, a blood sample (0.5 mL) is collected and injected along the tube wall into a Helena test tube. The tube is then rotated at 20 rpm in a 37°C water bath until the blood coagulates. Based on the measured activated clotting time, the fluid pump 9 is adjusted to increase or decrease the heparin infusion rate to maintain a control range of 300-400 seconds. The fluid pump 9 is connected to the main unit and the display screen, and pump speed adjustment is not limited to buttons or a touchscreen. To balance the negative pressure generated by each sampling operation, an equal volume of normal saline is injected into the internal pressure regulating device simultaneously with the sampling.

[0070] Among them, the use time evaluation

[0071] During the blood filtration operation, the pre-filtration pressure is continuously recorded using the pre-filtration pressure gauge 16, and 150 mmHg is set as the threshold. The time to reach this value is regarded as the use time of the filter, and a time t-pre-filtration pressure p change curve is drawn.

[0072] In some embodiments, a suction bottle assembly was prepared to serve as a liquid storage chamber. The assembly was divided into two chambers: one chamber, with a capacity of 2 L, was used to hold the heparin solution; the other chamber contained a 2 L waste bag, which was connected to an external filtrate line. The waste bag was made of polyvinyl chloride and had a thickness of 1 mm. In an in vitro simulation of continuous hemofiltration, a separate pump continuously infused the heparin solution into a closed blood circulation circuit. Under pressure, an equal amount of filtrate automatically entered the waste bag. An initial pre-filtration pressure of 70 mmHg and a venous pressure of 7 mmHg were maintained using a resistance-applying device and venous elastic tubing. During the experiment, the pre-filtration pressure was continuously monitored using a diaphragm manometer. Blood samples were collected at 0, 1, 3, 6, 12, 24, 36, and 48 hours to monitor the activated clotting time. The time it took for the pre-filtration pressure to reach 150 mmHg was considered the filter life.

[0073] By cleverly utilizing the suction bottle and bag-type structure, a single fluid pump 9 can achieve equal injection of anticoagulant and discharge of filtrate, avoiding flow rate errors between pumps, simplifying the operation process, reducing operational errors, and making operation simpler, more convenient, and more accurate. This ensures that the pressure of the circulating blood circuit is not disturbed by the injection of anticoagulant, making the in vitro evaluation system for the service life of the hemofilter 1 more stable and accurate. This device has broad market demand and good application prospects, and possesses higher practical value.

[0074] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0075] The above description of the disclosed embodiments will enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A system for evaluating a hemofilter, characterized in that include: A blood supply passage, the outlet of which is connected to the blood chamber inlet of the blood filter, and the blood supply passage is provided with a sampling port and an anticoagulant infusion bypass; A blood return passage, the inlet of which is used to communicate with the blood chamber outlet of the blood filter; a filtrate bypass, wherein the inlet of the filtrate bypass is used to communicate with the filtrate outlet of the hemofilter, and the filtrate bypass has a filtrate suction bypass for sucking the filtrate; a liquid storage chamber, the liquid storage chamber being divided into a first chamber and a second chamber by a partition structure, wherein at least a portion of the partition structure is a soft membrane structure capable of deforming along with the pressure difference between the two sides to expand the chamber on the side with higher pressure and shrink the chamber on the side with lower pressure; The inlet of the anticoagulant infusion bypass is connected to the first chamber, and the outlet of the filtrate suction bypass is connected to the second chamber; at least one of the anticoagulant infusion bypass (5) and the filtrate suction bypass (6) is provided with a fluid pump.

2. The system for evaluating a hemofilter according to claim 1, wherein: The soft film structure is constructed as a bag-type structure, which is arranged in the liquid storage cavity; one of the first chamber and the second chamber is the inner cavity of the bag-type structure, and the other is the cavity between the liquid storage cavity wall and the bag-type structure.

3. The system for evaluating a hemofilter according to claim 2, wherein: The inner cavity of the bag-type structure is the second chamber, and the cavity between the bag-type structure and the wall of the liquid storage chamber is the first chamber.

4. The system for evaluating a hemofilter according to claim 3, wherein: The liquid storage container includes a glass bottle, and the bag-type structure is located in the glass bottle cavity; the filtrate suction bypass passes through the bottle mouth stopper of the glass bottle to be inserted into the bag mouth of the bag-type structure, and a drainage opening is provided on the side wall of the glass bottle to connect to the inlet of the anticoagulant infusion bypass.

5. The system for evaluating a hemofilter according to claim 4, wherein: The glass bottle is a conical bottle, and the drainage opening is arranged at the bottom of the glass bottle.

6. The system for evaluating a hemofilter according to claim 5, wherein: A closable communicating tube is provided at the bottle mouth of the glass bottle to communicate with the glass bottle cavity.

7. The system for evaluating a hemofilter according to any one of claims 1 to 6, characterized in that: An internal pressure regulating device is also included, the outlet of which is communicated with the inlet of the blood supply passage, and the inlet of which is communicated with both the outlet of the blood return passage and the outlet of the filtrate bypass.

8. The system for evaluating a hemofilter according to claim 7, wherein: The blood supply passage is provided with a blood supply pump, and the sampling port and the inlet of the anticoagulant infusion bypass are both connected between the outlet of the blood supply passage and the blood supply pump.

9. The system for evaluating a hemofilter according to claim 8, wherein: The blood return path is provided with a resistance applying device, a venous pressure gauge and a venous simulation elastic tube in sequence along the fluid direction.

10. The system for evaluating a hemofilter according to claim 9, wherein: It also includes a heating device; the blood delivery pathway is provided with the blood delivery pump, the sampling port, the arterial pot and the pre-filtration pressure gauge along the blood delivery direction; the inlet of the anticoagulant infusion bypass is connected between the sampling port and the arterial pot; the venous pressure gauge, the venous simulation elastic tube and the internal pressure regulating device are all provided in the heating area of ​​the heating device; the anticoagulant infusion bypass and the filtrate suction bypass are both provided with the fluid pump; and the filtrate bypass is provided with a filtrate pump.

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