An automated peritoneal dialysis machine support system designed to prevent peritoneal protein loss.

Abstract

This invention relates to an auxiliary system for an automated peritoneal dialysis machine that prevents protein loss from the peritoneal cavity. Belonging to the field of peritoneal dialysis technology, the system incorporates an auxiliary system with a hollow fiber membrane filter. During the drainage phase, peritoneal drainage fluid is introduced into the hollow fiber membrane filter, which utilizes its semi-permeable membrane properties to trap proteins while allowing small-molecule metabolic waste to pass through, forming a protein-rich filtrate. The control system dynamically adjusts the return pump speed based on flow sensor signals, ensuring that the protein-rich fluid return process is stably synchronized with the drainage, injection, and retention phases of the automated peritoneal dialysis machine. This achieves online protein recovery and safe return, solving the problem of continuously and selectively recovering and safely returning protein from peritoneal drainage fluid while coordinating with the treatment cycle of the automated peritoneal dialysis machine, thereby directly reducing the problem of protein nutritional loss in long-term peritoneal dialysis patients.

Description

Technical Field

[0001] This invention belongs to the field of peritoneal dialysis technology, specifically relating to an auxiliary system for an automated peritoneal dialysis machine that prevents the loss of peritoneal proteins. Background Technology

[0002] In the field of peritoneal dialysis, in order to optimize treatment outcomes or address specific clinical conditions, there are existing ideas for extracorporeal treatment of the drained peritoneal dialysis fluid. For example, in the treatment of peritoneal dialysis-associated peritonitis, some studies have proposed using blood filters or adsorption devices to circulate the peritoneal dialysis fluid extracorporeally to remove inflammatory cytokines, and then reinfusing the treated fluid to control the inflammatory response within the peritoneal cavity. In addition, in experimental systems that improve solute clearance efficiency, such as some continuous flow peritoneal dialysis models, dialyzer-like devices are used to construct closed-loop circulation. The core objective is to achieve continuous and efficient clearance of small molecule toxins (such as urea and creatinine) or reduce the total consumption of dialysis fluid. In these existing technical solutions, large molecules (such as proteins) are retained during circulation, which is usually a byproduct of achieving the main technical objectives (such as maintaining circulatory pathways or avoiding excessive dilution of nutrients), rather than the core objective actively pursued and optimized by the technical solution.

[0003] However, the aforementioned existing technologies have inherent limitations, making them unable to effectively address the specific clinical problem of peritoneal protein nutritional loss faced by long-term peritoneal dialysis patients. Firstly, these technologies were not designed with the specific aim of retaining and recovering nutritional proteins such as albumin in mind; rather, they focus on removing specific substances or improving the clearance efficiency of small-molecule toxins. Their system design and parameters, such as membrane pore size, transmembrane pressure, and flow path design, are not specifically configured to maximize the removal of small-molecule metabolic waste while optimizing the retention of large-molecule proteins. Secondly, these solutions typically exist as independent, temporary treatment modules or complex experimental systems, and are not a system that can be integrated with conventional automated peritoneal dialysis. There is a lack of standardized auxiliary devices that are seamlessly integrated into the peritoneal dialysis machine and operate stably and easily during each dialysis cycle. Therefore, although there is a broad concept of extracorporeal treatment of peritoneal dialysis fluid, there is still a lack of a technical solution specifically for the treatment scenario of automated peritoneal dialysis machines that aims to directly reduce protein loss and can continuously and selectively recover proteins from the waste fluid side and safely return them to the patient's peritoneal cavity during routine dialysis through an online filtration and separation mechanism. This has resulted in a lack of direct, effective and easily integrated intervention methods for the problem of protein loss associated with peritoneal dialysis in clinical practice. In response, an auxiliary system for automated peritoneal dialysis machines that prevents peritoneal protein loss is proposed. Summary of the Invention

[0004] To address the aforementioned problems in the existing technology, this invention provides an automated peritoneal dialysis machine auxiliary system that prevents the loss of peritoneal protein. This system solves the problem of how to continuously and selectively recover and safely return protein from peritoneal drainage fluid while coordinating with the treatment cycle of the automated peritoneal dialysis machine, thereby directly reducing the problem of nutritional protein loss in long-term peritoneal dialysis patients.

[0005] The objective of this invention can be achieved through the following technical solution: an auxiliary system for an automated peritoneal dialysis machine that prevents the loss of peritoneal proteins, comprising a control system, a pre-filtration drainage line, a hollow fiber membrane filter, and a post-filtration drainage line. The two ends of the hollow fiber membrane filter are respectively connected to the output end of the pre-filtration drainage line and the input end of the post-filtration drainage line. The input end of the pre-filtration drainage line is connected to the patient's peritoneal drainage end of the automated peritoneal dialysis machine, and the output end of the post-filtration drainage line is connected to the patient's peritoneal return end of the automated peritoneal dialysis machine. A heparinized saline flushing branch is connected in parallel on the pre-filtration drainage line. The membrane filter housing has a channel on its side wall, and the channel is connected to a waste liquid bag through a waste liquid discharge device. The filtered drainage pipeline is equipped with a water flow sensor, a regulating pump, and an anti-backflow check valve in sequence from the input end to the output end. The control system is connected to the water flow sensor and the regulating pump respectively. The control system receives the real-time flow signal detected by the water flow sensor and controls the operation of the regulating pump based on the signal to adjust the return flow rate of the liquid in the filtered drainage pipeline, thereby coordinating with the treatment cycle of the automatic peritoneal dialysis machine and ensuring that the protein-rich filtered liquid is stably and controllably reinfused back into the patient's peritoneal cavity.

[0006] As a further embodiment of the present invention, the heparin saline flushing branch includes heparin saline and a flow rate controller disposed on one side of the pre-filtration drainage pipeline, wherein the heparin saline is connected to the pre-filtration drainage pipeline through the flow rate controller.

[0007] As a further embodiment of the present invention, the control system includes a first pressure sensor disposed on the pre-filtration drainage pipeline and a second pressure sensor disposed on the post-filtration drainage pipeline. The control system is connected to the first pressure sensor, the second pressure sensor and the water flow sensor. Based on the first pressure difference value of the first pressure sensor and the second pressure sensor and the first flow value of the water flow sensor, an initial flow resistance baseline is established. The real-time pressure difference and real-time flow value are acquired in real time, and the real-time flow resistance is calculated. The real-time flow resistance is compared with the initial flow resistance baseline. Based on whether the absolute increase value of the real-time flow resistance exceeds the maximum allowable flow resistance threshold, it is determined whether the hollow fiber membrane filter or related pipeline is blocked. Based on whether the rate of change of the real-time flow resistance over time exceeds the flow resistance rise rate threshold, it is determined whether it is acute mechanical obstruction or chronic progressive membrane fouling.

[0008] As a further embodiment of the present invention, the control system includes a safety protection module, which is connected to the water flow sensor and the regulating pump. The safety protection module includes a pump stop control unit, an alarm unit, and a return flow pause unit.

[0009] As a further embodiment of the present invention, the control system includes a prescription parameter storage unit and a stage control unit. The stage control unit sets the pump speed in segments for the drainage stage, the injection stage and the residence stage, and performs speed transition control when switching stages.

[0010] As a further embodiment of the present invention, the fiber cavity of the hollow fiber membrane filter is a peritoneal dialysis effluent channel, the side wall channel of the hollow fiber membrane filter shell is a waste liquid channel and is connected to a waste liquid bag via a waste liquid discharge device, and the membrane of the hollow fiber membrane filter is a semi-permeable membrane, which has the characteristics of protein retention and permeability to small molecules.

[0011] As a further embodiment of the present invention, the heparin saline flushing branch is equipped with an adjustable valve, which has three working states: pre-filling, intermittent flushing, and final flushing.

[0012] As a further embodiment of the present invention, the control system includes a return metering module, which is connected to a water flow sensor and a regulating pump. The return metering module includes a volume integration unit and a target volume setting unit.

[0013] As a further embodiment of the present invention, the first pressure sensor is disposed at the proximal end of the pre-filtration drainage pipeline near the hollow fiber membrane filter, and the second pressure sensor is disposed between the regulating pump and the anti-backflow check valve.

[0014] As a further embodiment of the present invention, the anti-reflux check valve is located near the proximal end of the patient's peritoneal return end of the automated peritoneal dialysis machine, and its opening direction is towards the patient's peritoneal return end. The anti-reflux check valve has an anti-siphon structure that limits the opening pressure.

[0015] The beneficial effects of this invention are as follows:

[0016] This invention incorporates an auxiliary system including a hollow fiber membrane filter. During the drainage stage, peritoneal drainage fluid is introduced into the hollow fiber membrane filter, which utilizes its semi-permeable membrane properties to retain proteins while allowing small molecule metabolic waste to pass through, forming a protein-rich filtrate. The control system then dynamically adjusts the return pump speed based on flow sensor signals, ensuring that the protein fluid return process is stably synchronized with the drainage, injection, and retention stages of the automated peritoneal dialysis machine, achieving online protein recovery and safe return. Attached Figure Description

[0017] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0019] Explanation of key component symbols:

[0020] In the diagram: 1. Automated peritoneal dialysis machine; 2. Heparinized saline solution; 3. Flow rate controller; 4. Hollow fiber membrane filter; 5. Waste liquid discharge device; 6. Waste liquid bag; 7. Water flow sensor; 8. Regulating pump; 9. Anti-backflow check valve; 10. Peritoneal dialysis fluid. Detailed Implementation

[0021] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided.

[0022] Please see Figure 1 This embodiment provides an auxiliary system for an automated peritoneal dialysis machine 1 that prevents the loss of peritoneal proteins. The system includes a control system, a pre-filtration drainage line, a hollow fiber membrane filter 4, and a post-filtration drainage line. Both ends of the hollow fiber membrane filter 4 are connected to the output end of the pre-filtration drainage line and the input end of the post-filtration drainage line, respectively. The input end of the pre-filtration drainage line is connected to the patient's peritoneal drainage end of the automated peritoneal dialysis machine 1, and the output end of the post-filtration drainage line is connected to the patient's peritoneal reinfusion end of the automated peritoneal dialysis machine 1. A heparinized saline flushing branch 2 is connected in parallel on the pre-filtration drainage line. A hole is formed on the side wall of the hollow fiber membrane filter 4 housing. The system includes a channel connected to a waste bag 6 via a waste discharge device 5. A water flow sensor 7, a regulating pump 8, and an anti-backflow check valve 9 are sequentially installed on the filtered drainage line from the input to the output. The control system is connected to the water flow sensor 7 and the regulating pump 8. The control system receives the real-time flow signal detected by the water flow sensor 7 and controls the operation of the regulating pump 8 based on this signal to adjust the return flow rate of the fluid in the filtered drainage line, thereby coordinating with the treatment cycle of the automatic peritoneal dialysis machine 1. This ensures that the protein-rich filtered fluid is stably and controllably reinfused back into the patient's peritoneal cavity. The system also includes peritoneal dialysis fluid 10, such as… Figure 1As shown, peritoneal dialysis fluid 10 is located at the very end of the filtered drainage tubing, specifically after the anti-reflux check valve 9 and directly connected to the patient's peritoneal return end of the automatic peritoneal dialysis machine 1. Its function is to represent the final product after the entire process of this auxiliary system, namely, "protein-rich filtered fluid". This fluid is drawn from the patient's peritoneal cavity during the drainage stage, and is formed after the hollow fiber membrane filter 4 selectively retains proteins and removes small molecule metabolic waste. After a series of processes such as flow and pressure regulation, safety monitoring, and metering verification, it is finally safely and unidirectionally returned to the patient's peritoneal cavity through the anti-reflux check valve 9 with an anti-siphon structure, thereby directly achieving the purpose of supplementing protein nutrition and reducing protein loss in long-term peritoneal dialysis patients.

[0023] It should be further explained that an auxiliary system for an automated peritoneal dialysis machine 1 designed here to prevent the loss of peritoneal proteins is introduced. A hollow fiber membrane filter 4 is introduced. The membrane of this filter has the characteristic of retaining proteins. Its working principle is as follows: when the dialysate (containing metabolic waste and protein) drained from the patient's peritoneal cavity flows through this filter, small molecule metabolic waste (such as urea and creatinine) can pass through the membrane wall into the shell side and eventually be discharged as waste liquid; while large molecule proteins such as albumin are selectively retained in the fiber lumen, forming "protein-rich filtered liquid". This directly realizes the core function of separating and retaining proteins from waste at the source. A control system and a water flow sensor are also designed. The closed-loop control circuit consisting of pump 7 and regulating pump 8 monitors the fluid flow rate in the reinfusion line in real time through water flow sensor 7. The control system receives the flow rate signal and controls the operation of regulating pump 8 based on this. By dynamically adjusting the speed of pump 8, the control system can precisely control the reinfusion rate and timing of protein-rich fluid. This allows it to actively coordinate with the treatment phases (drainage, injection of fresh dialysate, peritoneal retention) of the automated peritoneal dialysis machine 1. For example, reinfusion can be started synchronously when the main unit performs drainage; the reinfusion rate can be paused or reduced when the main unit infuses fresh dialysate into the peritoneal cavity to avoid conflicts. This ensures that the protein recovery process is seamlessly integrated into the standard treatment process, rather than being a separate and disruptive operation.

[0024] Currently, existing technologies exist for the extracorporeal treatment of peritoneal dialysis effluent, but their core objective is to remove inflammatory factors or improve the clearance efficiency of small molecule toxins. The retention of proteins is merely a byproduct, not an active optimization goal. More importantly, these solutions are mostly independent or experimental modules, which cannot achieve stable, convenient, and seamless integration and collaborative work with conventional automated peritoneal dialysis machines in each treatment exchange cycle. As a result, there is still a lack of a direct, effective, and dedicated intervention method that can be integrated into the daily treatment process to address the problem of protein nutritional loss associated with peritoneal dialysis.

[0025] To address the aforementioned issues, this embodiment employs an auxiliary system including a hollow fiber membrane filter 4. During the drainage phase, peritoneal drainage fluid is introduced into the hollow fiber membrane filter 4, utilizing its semi-permeable membrane properties to trap proteins while allowing small-molecule metabolic waste to pass through, resulting in a protein-rich filtrate. The control system dynamically adjusts the return pump speed based on flow sensor signals, ensuring stable synchronization between the protein filtrate return process and the drainage, injection, and retention phases of the automated peritoneal dialysis machine 1, achieving online protein recovery and safe return. The hollow fiber membrane here uses biocompatible polysulfone or polyethersulfone as the substrate. A support layer with high porosity and uniform pore size distribution is prepared using a non-solvent-induced phase separation method. On the surface of this support layer, a highly hydrophilic material is introduced through surface grafting or covalent modification techniques. With its anti-protein adsorption properties, the functional coating effectively reduces non-specific protein adsorption and deposition on the membrane surface, significantly improving the membrane's antifouling performance and long-term operational stability. Furthermore, a selective separation layer with precise molecular weight cutoff is constructed on top of the functional coating, achieving efficient retention of medium- and high molecular weight proteins such as albumin, while ensuring rapid permeation of small molecule metabolic wastes such as urea and creatinine. In addition, the overall membrane structure can be designed as a gradient pore or asymmetric multilayer structure, with the pore size gradually decreasing from the inlet side to the outlet side, avoiding internal blockage and enhancing separation efficiency. This results in excellent protein recovery, stable flux maintenance, and long-lasting antifouling performance during continuous peritoneal dialysis fluid treatment, making it a dedicated core filter material suitable for automated peritoneal dialysis support systems.

[0026] Because membrane fouling is an unavoidable physicochemical process in working environments with long-term contact with the target retentate (protein), the hollow fiber membrane filter 4 is highly susceptible to protein adsorption and aggregation, leading to deposition or blockage on its membrane surface and internal channels. This results in decreased filtration efficiency, increased flow resistance, and ultimately jeopardizes the continuous and stable operation of the system. To address this issue, in this embodiment, the heparinized saline 2 flushing branch includes heparinized saline 2 and a flow rate controller 3 located on one side of the pre-filtration drainage pipeline. The heparinized saline 2 is connected to the pre-filtration drainage pipeline via the flow rate controller 3. The flow channels are interconnected, and its design principle is as follows: the mixture of anticoagulant (heparin) and flushing solution (physiological saline) is injected into the pre-filtration pipeline and hollow fiber membrane filter 4 in a controllable manner periodically or as needed through the flow rate controller 3. Heparin can inhibit protein aggregation and fibrin formation, reducing their adhesion to the membrane surface; physiological saline provides mechanical flushing force to physically remove loose deposits. This combined effect of chemical anticoagulation and physical flushing can maintain membrane permeability and flow channel patency. This auxiliary maintenance function is introduced to ensure system reliability when membrane separation technology is applied to protein enrichment scenarios.

[0027] Furthermore, although the system achieves online protein recovery and the heparin flushing branch can delay membrane fouling, in actual operation, complex factors such as gradual protein adsorption, fibrin clot formation, or the occasional entry of large particles can cause unpredictable changes in the flow resistance of the hollow fiber membrane filter 4 or pipeline. If these changes cannot be identified and distinguished in a timely and accurate manner, they may lead to unstable reinfusion flow and decreased treatment efficiency, or even complete blockage causing equipment failure or treatment interruption, or even pose a safety risk to the patient due to abnormal pressure. In one embodiment, the control system includes a first pressure sensor installed on the pre-filtration drainage pipeline and a second pressure sensor installed on the post-filtration drainage pipeline. The control system is connected to the first pressure sensor, the second pressure sensor, and the water flow sensor 7. Based on the first pressure difference value of the first pressure sensor and the second pressure sensor and the first flow value of the water flow sensor 7, an initial flow resistance baseline is established. The real-time pressure difference and real-time flow value are acquired in real time, and the real-time flow resistance is calculated. The real-time flow resistance is compared with the initial flow resistance baseline, and the flow resistance is adjusted according to the real-time flow rate. The system determines whether the hollow fiber membrane filter 4 or related pipelines are blocked by checking whether the absolute increase in flow resistance exceeds the maximum allowable flow resistance threshold. It also determines whether the flow resistance rate of change exceeds the flow resistance rise rate threshold to distinguish between acute mechanical obstruction and chronic progressive membrane fouling. Flow resistance, a comprehensive physical quantity, is introduced as a core diagnostic indicator. By establishing an initial flow resistance baseline, the system possesses a personalized "health record." Real-time calculation of the absolute increase in flow resistance allows for sensitive detection of significant flow obstructions caused by any reason (such as acute thrombosis or foreign body blockage). Analyzing the rate of change in flow resistance intelligently distinguishes between acute events (such as mechanical obstruction, which has a fast rate) and chronic processes (such as membrane fouling, which has a slow rate). This dual-criteria design enables the control system not only to detect "already occurred" severe blockages but also to warn of "developing" performance degradation. This provides precise data support for taking differentiated maintenance measures, such as triggering enhanced flushing or prompting preventative filter replacement. It is a key intelligent diagnostic module ensuring the long-term reliable, safe, and automated operation of the entire auxiliary system.

[0028] Furthermore, although flow resistance monitoring can accurately diagnose acute obstruction or chronic contamination, if the system only focuses on diagnosis and cannot automatically perform treatment or intervention, serious abnormalities still rely on immediate detection and manual handling by operators. This poses risks of response delays, operational errors, or lack of monitoring in clinical settings, potentially leading to continuous operation of the regulating pump 8 under blockage or high pressure conditions, causing secondary hazards such as pipe rupture, filter damage, and unsafe pressure entering the patient's abdominal cavity, ultimately threatening treatment safety and equipment integrity. In one embodiment, the control system includes a safety protection module connected to the water flow sensor 7 and the regulating pump 8. The safety protection module includes a pump stop control unit, an alarm unit, and a return flow pause unit. When the real-time flow resistance exceeds the maximum allowable flow... When the flow resistance threshold or the rate of increase in flow resistance exceeds the flow resistance increase rate threshold, the pump is automatically stopped, an audible and visual alarm is issued, and the reinfusion process is suspended until the pipeline flushing is completed or manual confirmation is performed before operation can resume. When the monitoring module determines that the real-time flow resistance or the rate of change exceeds the safety threshold, the safety protection module immediately takes over: the pump stop control unit cuts off the power source to fundamentally prevent the situation from deteriorating; the alarm unit actively reminds personnel to intervene through audible and visual signals; and the reinfusion suspension unit locks the pipeline to avoid abnormal fluid infusion. This design ensures an automatic, immediate, and reliable transition from risk identification to safety shutdown, which is the core embodiment of the fail-safe principle in medical equipment design. It solves the fundamental need of automated systems to ensure patient safety in the absence of immediate human intervention, upgrading the entire auxiliary system from intelligent assistance to safe and reliable medical equipment.

[0029] If the reinfusion process operates at a fixed speed or with simple start-stop cycles, it will be unable to adapt to the complex and variable phase transitions in actual treatment. For example, when the main unit rapidly switches from the drainage phase to the infusion phase, if the reinfusion pump of the auxiliary system does not slow down and stop in a timely and smooth manner, it may cause fluid conflict with the freshly infused dialysate at the entrance to the patient's peritoneum or in the tubing, leading to pressure fluctuations, uneven mixing, or even treatment errors. In the residence phase, completely stopping the reinfusion may cause protein fluid retention at the end of the tubing, while continuous high-speed reinfusion may unduly disturb the intraperitoneal environment. To address this, in one embodiment, the control system includes a prescription parameter storage unit and a phase control unit. The phase control unit sets the pump speed in segments for the drainage, infusion, and residence phases, and performs speed transition control during phase transitions. The control system stores a reinfusion control curve that matches the treatment prescription of the automated peritoneal dialysis machine 1. Reinfusion is initiated during the drainage phase and during the infusion phase... The system features a phased pause infusion process. During the pause phase, infusion is maintained or paused at a low speed according to a pre-defined setting. The system also provides smooth transition control of the pump speed 8 during phase transitions to coordinate with the treatment cycle. The prescription parameter storage unit is a database or memory module that stores specific treatment mode parameters (such as preset durations for each phase and target infusion rates). This allows the system to recognize and call upon the expected timing that perfectly matches the current treatment prescription of the host machine. Based on this, the phase control unit can execute advanced coordination strategies: active infusion during the drainage phase, pause during the infusion phase to avoid conflicts, and provide a flexible choice of maintaining or pausing at a low speed during the pause phase. Crucially, it performs smooth transition control of the pump speed during phase transitions, avoiding sudden changes in flow and pressure. This achieves both logical synchronization with the host machine's treatment cycle and smooth fluid dynamic connection. The host machine refers to the main body of the automated peritoneal dialysis machine 1.

[0030] To avoid issues related to separation path optimization and efficiency assurance required for the system to achieve its core filtration function, in one embodiment, the fiber cavity of the hollow fiber membrane filter 4 serves as the peritoneal effluent channel, the side wall channel of the shell of the hollow fiber membrane filter 4 serves as the waste liquid channel and is connected to the waste liquid bag 6 via the waste liquid discharge device 5, and the membrane of the hollow fiber membrane filter 4 is a semi-permeable membrane. The semi-permeable membrane has protein retention characteristics and is permeable to small molecules. The membrane of the hollow fiber membrane filter 4 uses a dispersion or convection separation mechanism to allow small molecule solutes to preferentially permeate to the shell-side waste liquid, while effectively retaining proteins to form... The filtered fluid is rich in protein. By clearly dividing the fiber lumen into a channel for protein-containing peritoneal dialysis fluid and the shell side into a waste fluid channel, and using a semi-permeable membrane with specific selective permeability, the flow of peritoneal dialysis fluid within the fiber lumen is ensured. Small molecule waste permeates through the membrane into the shell side via diffusion / convective mass transfer, while proteins are retained due to size or charge effects. This achieves continuous and efficient separation during a single flow. The clear flow channel division prevents insufficiently treated fluid from short-circuiting into the return end, ensuring that waste fluid is collected directionally into the waste fluid bag 6, while the "protein-rich filtered fluid" is safely returned to the patient.

[0031] Because membrane fouling and clogging is a dynamic, cumulative process that occurs before, during, and after treatment: before treatment, air or particles may be present in the tubing, and failure to pre-fill and vent them can easily lead to airflow blockage or initial contamination; during treatment, substances such as proteins will continuously adsorb and deposit, requiring periodic intermittent flushing to prevent progressive clogging; after treatment, if the residual fluid is not cleaned, proteins may solidify, increasing the risk of clogging in subsequent treatments. If the flushing branch only has a simple on / off function and cannot implement differentiated and automated flushing strategies for the different stages of contamination, the anti-clogging effect will be limited. Therefore, in one embodiment, the heparinized saline 2 flushing branch is equipped with an adjustable valve. The adjustable valve has three working states: pre-filling, intermittent flushing, and final flushing. The heparinized saline 2 flushing branch is configured to perform pre-filling and venting before treatment, and during treatment... Intermittent pulse flushing is performed according to the set frequency and duration, and a final flush is performed after treatment to reduce the risk of blockage caused by fibrin deposition and membrane fouling. By adding an adjustable valve with three working states—pre-filling, intermittent flushing, and final flushing—to the heparin saline flushing branch, the problems of single flushing strategy, fixed timing, and low automation in the flushing branch design when achieving anti-clogging function are solved, which may lead to incomplete and inaccurate membrane fouling control. Through multi-state programming of the adjustable valve, full-cycle intelligent active maintenance is achieved: the pre-filling state ensures clean air venting of the pipeline before treatment, the intermittent pulse flushing dynamically removes fresh deposits during treatment, and the final flushing thoroughly removes residues after treatment, thereby systematically reducing the risk of blockage at each stage and improving the reliability and service life of the auxiliary system.

[0032] To avoid potential issues with inaccurate infusion volume and lack of closed-loop control during protein reinfusion, which could affect treatment safety and protein recovery integrity, in one embodiment, the control system includes an infusion metering module connected to a water flow sensor 7 and a regulating pump 8. The metering module includes a volume integration unit and a target volume setting unit. Based on the output of the water flow sensor 7, the metering module integrates and measures the infusion volume, records the cumulative infusion volume for each treatment cycle, and automatically reduces or stops the regulating pump 8 when the preset target volume is reached. By adding an infusion metering module to the control system, which includes a volume integration unit and a target volume setting unit, the volume integration unit converts the flow signal into accurate cumulative volume data in real time, and the target volume setting unit provides personalized quantitative standards. This upgrade from flow rate control to volume closed-loop control ensures that the preset amount of protein fluid is automatically and accurately reinfused in each treatment cycle. While improving the automation level of treatment, this system also ensures the integrity of the therapeutic effect and patient safety. Furthermore, this system introduces adaptive features based on individual patient differences. The adaptive reinfusion strategy integrates multi-dimensional information such as patient clinical data (e.g., protein loss rate and serum albumin level from previous treatment records), human parameters (e.g., dry weight and body surface area), and current dialysis prescription (e.g., dialysate exchange volume, retention time, and glucose concentration). The intelligent algorithm built into the control system dynamically calculates the expected protein loss for each patient within the treatment cycle and personalizes the target volume and flow rate curve for protein recovery and reinfusion for that cycle. During actual treatment, the system continuously compares the actual recovered protein amount with the expected loss by monitoring the protein concentration in the drainage fluid in real time (optionally estimated indirectly by a biosensor) and the reinfusion flow rate. It also automatically fine-tunes the speed and start / stop sequence of the anatomical pump based on the treatment stage (drainage, infusion, retention) and the trend of intra-abdominal pressure changes, thereby maximizing protein reinfusion efficiency within a safe range. This adaptive strategy not only avoids insufficient supplementation or overload caused by fixed reinfusion parameters but also self-optimizes as the patient's condition changes and the dialysis plan is adjusted, truly forming a patient-centered closed-loop nutritional management system that improves the treatment quality and patient prognosis of long-term peritoneal dialysis.

[0033] It is worth mentioning that, since the accuracy of flow resistance calculation directly depends on the measurement quality of the pressure difference, if the first pressure sensor is too far from the inlet of the hollow fiber membrane filter 4, its reading will include unnecessary pressure loss along the pipeline, leading to an overestimation of the filter's true pressure drop. If the second pressure sensor is improperly positioned, it cannot accurately reflect the final pressure state after being pressurized by the regulating pump 8 and before being reinfused into the patient's abdominal cavity. This measurement deviation will cause the aforementioned flow resistance baseline to fail and the threshold judgment to be inaccurate, thus affecting the reliability of the blockage diagnosis. In peritoneal dialysis treatment, changes in patient position or changes in abdominal pressure may generate instantaneous negative pressure at the abdominal end. If only a common one-way valve is used at the end of the reinfusion pipeline, this negative pressure may be sufficient to open the valve, leading to two dangerous situations: one is that the fluid that has been reinfused or is in the abdominal cavity is drawn back into the pipeline system, causing secondary contamination or inaccurate treatment dosage; more seriously, a siphon effect may occur. Continuous drainage of fluid from the peritoneal cavity can even lead to air ingress, seriously threatening patient safety and the integrity of the treatment loop. Therefore, in order to further avoid measurement error interference and fluid backflow risk while achieving the two core goals of high-precision flow resistance monitoring and absolute reinfusion safety, in one embodiment, a first pressure sensor is set at the proximal end of the pre-filtration drainage line near the hollow fiber membrane filter 4, and a second pressure sensor is set between the regulating pump 8 and the anti-backflow check valve 9 to improve the accuracy of the judgment of filter pressure drop and reinfusion side pressure changes. The anti-backflow check valve 9 is set at the proximal end of the patient's peritoneal reinfusion end near the automatic peritoneal dialysis machine 1, and its opening direction is towards the patient's peritoneal reinfusion end. The anti-backflow check valve 9 has an anti-siphon structure that limits the opening pressure. By placing the first pressure sensor at the proximal end of the filter inlet, the inlet pressure of the filter can be directly measured, eliminating upstream pipeline resistance interference to the greatest extent.The second pressure sensor is placed after the regulating pump 8 and before the anti-backflow check valve 9 to directly measure the pressure of the fluid about to enter the patient's abdominal cavity. This arrangement allows the pressure difference between the two sensors to more accurately reflect the total flow resistance of the entire core processing and delivery path from the filter inlet to the abdominal return point, greatly improving the accuracy and reliability of flow resistance calculation and blockage diagnosis. The anti-backflow check valve 9 is placed near the proximal end of the return end, closest to the patient's abdominal cavity, establishing a final physical barrier. This valve not only prevents backflow, but its opening requires overcoming a set positive pressure threshold. This design effectively prevents accidental valve opening due to occasional negative pressure at the abdominal end, thus completely eliminating the possibility of fluid backflow or dangerous siphoning, ensuring that fluid can only enter the abdominal cavity in a unidirectional and controlled manner. This system further integrates biological... The sensor module enables continuous, real-time monitoring of key biosafety indicators in the reinfusion fluid. This module is typically located in the post-filter drainage tubing between the regulating pump and the anti-backflow check valve. Its core utilizes detection technologies based on specific antigen-antibody reactions, molecular imprinting, or nanomaterial enhancement, such as fiber optic surface plasmon resonance sensors or electrochemical immunoassay sensors. These sensors specifically identify and quantify inflammatory factors, endotoxins, or microbial markers in the reinfusion fluid. Monitoring data is transmitted to the control system in real time. The system incorporates a safety criterion algorithm: when any indicator concentration exceeds a preset clinical safety threshold, the system immediately triggers multiple protective responses—automatically pausing the regulating pump and shutting down the reinfusion tubing, activating audible and visual alarms to alert medical staff, and clearly displaying the abnormal indicator and its potential clinical significance on the user interface. Furthermore, this module supports periodic automatic calibration and quality control self-checks to ensure reliable monitoring results. By deeply integrating real-time biosafety monitoring with automated control logic, this system effectively prevents the backflow of fluids containing potential inflammatory or infectious risks into the patient's peritoneal cavity during protein recovery. This ensures maximum safety and clinical controllability of peritoneal dialysis treatment while pursuing nutritional supplementation, making it particularly suitable for the refined treatment management of patients in the recovery phase of peritonitis or those with weakened immune systems.

[0034] Working principle and usage process of this invention:

[0035] During the drainage phase of routine treatment in the automated peritoneal dialysis machine 1, peritoneal drainage fluid rich in metabolic waste and protein is drawn out. It first flows through the pre-filtration drainage tubing of this auxiliary system and enters the hollow fiber membrane filter 4. In this filter, the drainage fluid flows through the fiber lumen. Utilizing the selective retention characteristics of the semi-permeable membrane, small-molecule metabolic waste molecules diffuse or convect through the membrane into the shell side and are ultimately discharged as waste fluid. Large-molecule proteins such as albumin are effectively retained within the fiber lumen, forming a protein-rich filtrate. Subsequently, this filtrate enters the post-filtration drainage tubing, where the flow rate is monitored in real time by the water flow sensor 7. The control system dynamically adjusts the speed of the downstream regulating pump 8 based on this signal, thereby precisely controlling the reinfusion rate. This ensures that the protein fluid reinfusion process aligns with the treatment cycle of the automated peritoneal dialysis machine 1, encompassing drainage, infusion, and retention phases. The system features active coordination and smooth transitions. Throughout the process, the control system analyzes pressure sensor signals located near the filter inlet and downstream of the reinfusion pump to calculate system flow resistance in real time. It intelligently monitors and distinguishes between acute blockage and chronic membrane fouling risks. Once the safety threshold is exceeded, the safety protection module is triggered to automatically pause reinfusion and issue an alarm. Simultaneously, the heparinized saline flushing branch performs pre-filling, intermittent pulse flushing, and final flushing according to a preset program before, during, and after treatment to actively maintain membrane and tubing patency. The reinfusion metering module ensures that the volume of protein fluid reinfused each cycle accurately reaches the set target. Finally, the treated protein fluid is safely and unidirectionally returned to the patient's peritoneal cavity through the anti-backflow check valve 9 with an anti-siphon structure at the end, thereby achieving continuous online protein recovery during dialysis and effectively reducing nutritional loss.

[0036] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. An auxiliary system for an automated peritoneal dialysis machine that prevents the loss of peritoneal proteins, characterized in that, The system includes a control system, a pre-filtration drainage line, a hollow fiber membrane filter, and a post-filtration drainage line. The two ends of the hollow fiber membrane filter are connected to the output end of the pre-filtration drainage line and the input end of the post-filtration drainage line, respectively. The input end of the pre-filtration drainage line is connected to the patient's peritoneal drainage end of the automated peritoneal dialysis machine, and the output end of the post-filtration drainage line is connected to the patient's peritoneal return end of the automated peritoneal dialysis machine. A heparinized saline flushing branch is connected in parallel on the pre-filtration drainage line. A channel is opened on the side wall of the hollow fiber membrane filter housing, and the channel is connected to a waste liquid bag through a waste liquid discharge device. A water flow sensor, a regulating pump, and an anti-backflow check valve are sequentially installed on the post-filtration drainage line from the input end to the output end. The control system is connected to the water flow sensor and the regulating pump signal respectively. The control system receives the real-time flow signal detected by the water flow sensor and controls the operation of the regulating pump based on the signal to adjust the return flow rate of the fluid in the filtered drainage pipeline, thereby coordinating with the treatment cycle of the automatic peritoneal dialysis machine and ensuring that the protein-rich filtered fluid is stably and controllably reinfused back into the patient's peritoneal cavity. The control system includes a first pressure sensor installed on the pre-filtration drainage pipeline and a second pressure sensor installed on the post-filtration drainage pipeline. The control system is connected to the first pressure sensor, the second pressure sensor, and the water flow sensor. Based on the first pressure difference value of the first pressure sensor and the second pressure sensor and the first flow value of the water flow sensor, an initial flow resistance baseline is established. The real-time pressure difference and real-time flow value are acquired in real time, and the real-time flow resistance is calculated. The real-time flow resistance is compared with the initial flow resistance baseline. Based on whether the absolute increase value of the real-time flow resistance exceeds the maximum allowable flow resistance threshold, it is determined whether the hollow fiber membrane filter or related pipeline is blocked. Based on whether the rate of change of the real-time flow resistance over time exceeds the flow resistance rise rate threshold, it is determined whether there is acute mechanical obstruction or chronic progressive membrane fouling. The control system includes a prescription parameter storage unit and a stage control unit. The stage control unit sets the pump speed in segments for the drainage stage, the injection stage, and the residence stage, and performs speed transition control when switching stages. The control system includes a return metering module, which is connected to a water flow sensor and a regulating pump. The return metering module includes a volume integration unit and a target volume setting unit.

2. The automated peritoneal dialysis machine auxiliary system for preventing peritoneal protein loss according to claim 1, characterized in that, The heparinized saline flushing branch includes heparinized saline and a flow rate controller located on one side of the pre-filtration drainage line. The heparinized saline is connected to the pre-filtration drainage line through the flow rate controller.

3. The automated peritoneal dialysis machine auxiliary system for preventing peritoneal protein loss according to claim 1, characterized in that, The control system includes a safety protection module, which is connected to the water flow sensor and the regulating pump. The safety protection module includes a pump stop control unit, an alarm unit, and a return flow pause unit.

4. The automated peritoneal dialysis machine auxiliary system for preventing peritoneal protein loss according to claim 1, characterized in that, The hollow fiber membrane filter has a fiber cavity that serves as a peritoneal dialysis effluent channel, and a shell sidewall channel that serves as a waste liquid channel and is connected to a waste liquid bag via a waste liquid discharge device. The membrane of the hollow fiber membrane filter is a semi-permeable membrane, which has protein retention properties and permeability to small molecules.

5. An automated peritoneal dialysis machine auxiliary system for preventing peritoneal protein loss according to claim 2, characterized in that, The heparinized saline flushing branch is equipped with an adjustable valve, which has three working states: pre-filling, intermittent flushing, and final flushing.

6. An automated peritoneal dialysis machine auxiliary system for preventing peritoneal protein loss according to claim 1, characterized in that, The first pressure sensor is located near the hollow fiber membrane filter in the pre-filtration drainage line, and the second pressure sensor is located between the regulating pump and the anti-backflow check valve.

7. An automated peritoneal dialysis machine auxiliary system for preventing peritoneal protein loss according to claim 6, characterized in that, The anti-reflux check valve is located near the proximal end of the patient's peritoneal return end of the automated peritoneal dialysis machine, and its opening direction is towards the patient's peritoneal return end. The anti-reflux check valve has an anti-siphon structure that limits the opening pressure.

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