Semi-permeable membrane for hemodialysis and hemodialysis device

Abstract

The utility model provides a semipermeable membrane for hemodialysis and a hemodialysis device. Specifically, the semipermeable membrane sequentially comprises a first polyester fiber non-woven fabric supporting layer and a second polyester fiber non-woven fabric supporting layer, a first chitosan layer; a porous polysulfone membrane, wherein the average pore size of pores in the porous polysulfone membrane is in the range of 5 nm to 50 nm; a second chitosan layer; and a second polyester fiber non-woven fabric supporting layer. The semi-permeable membrane for hemodialysis has good biocompatibility, wider waste removal capacity (besides small molecular substances (such as urea and creatinine), middle molecular substances (such as beta2-microglobulin) can be effectively removed) and good durability.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, specifically to a semipermeable membrane for hemodialysis and a hemodialysis device. Background Technology

[0002] Hemodialysis is one of the most important renal replacement therapies for patients with end-stage renal disease. Its main principle is to draw the patient's blood out of the body and, with the help of a dialyzer (artificial kidney), utilize the solute concentration difference across the dialysis membrane to cause toxins and excess substances in the blood to diffuse into the dialysate. The purified blood then flows back into the body, thus partially replacing the function of the kidneys, removing metabolic waste, excess water, and electrolytes, maintaining acid-base balance and electrolyte stability, and ultimately prolonging the patient's life and improving their quality of life.

[0003] The semipermeable membrane in a dialyzer is a key component for blood purification. It allows small molecules (such as urea and creatinine) to pass through while blocking blood cells and large protein molecules, thus achieving selective removal. However, existing semipermeable membranes used in hemodialysis still have many areas for improvement.

[0004] First, some currently used semipermeable membranes suffer from poor biocompatibility. For example, some semipermeable membrane materials, especially early cellulose-based membranes, can trigger the activation of the human immune and coagulation systems upon contact with blood. The immune system recognizes the semipermeable membrane as a foreign object, leading to an inflammatory response. For instance, white blood cells may accumulate on the membrane surface and release inflammatory factors, causing symptoms such as fever and fatigue. Simultaneously, activation of the coagulation system increases the risk of thrombosis, which not only interferes with the normal dialysis process but can also lead to dialyzer blockage in severe cases. Furthermore, proteins in the blood readily adsorb onto the surface of semipermeable membranes. Adsorbed proteins alter membrane properties, such as reducing the effective pore size, thereby decreasing the dialysis efficiency for solutes, particularly affecting the removal of medium-molecular-weight substances.

[0005] Furthermore, some commercially available semipermeable membranes have limited effectiveness in removing medium-sized molecules. Specifically, traditional semipermeable membranes are primarily designed to remove small molecules (such as urea and creatinine), and their effectiveness in removing medium-sized molecules (such as β2-microglobulin) is not ideal. The accumulation of these medium-sized molecules in the body can harm patients, for example, by potentially inducing amyloidosis, which in turn affects the function of vital organs such as bones, joints, and the heart.

[0006] Furthermore, the durability of semipermeable membranes is a common concern. During long-term dialysis operations, semipermeable membranes may rupture or be damaged due to factors such as pressure fluctuations and chemical corrosion. Taking ultrafiltration as an example, if the pressure difference between the dialysate and blood sides is not properly controlled, the membrane may rupture, leading to blood mixing with the dialysate and causing serious medical accidents. Moreover, with increased use, the membrane's performance gradually deteriorates; for example, the membrane's pore size may change unreasonably, affecting the accuracy of dialysis.

[0007] In conclusion, developing a semipermeable membrane with excellent biocompatibility, a wider range of waste removal capabilities (effectively removing not only small molecules but also medium molecules such as β2-microglobulin) and good durability is of great practical significance. Utility Model Content

[0008] Based on the technical problems described above, one of the objectives of this utility model is to provide a semipermeable membrane for hemodialysis and a hemodialysis device. The semipermeable membrane for hemodialysis according to this utility model has good biocompatibility, a wider range of waste removal capabilities (effectively removing medium-molecular-weight substances (such as β2-microglobulin) in addition to small molecules (such as urea and creatinine)), and good durability.

[0009] Specifically, according to one aspect of the present invention, a semipermeable membrane for hemodialysis is provided, characterized in that the semipermeable membrane comprises, in sequence:

[0010] First polyester fiber nonwoven fabric support layer;

[0011] First chitosan layer;

[0012] A porous polysulfone membrane, wherein the average pore size of the pores in the porous polysulfone membrane is in the range of 5 nm to 50 nm;

[0013] Second chitosan layer; and

[0014] Second polyester fiber nonwoven fabric support layer.

[0015] Furthermore, according to another aspect of this utility model, a hemodialysis device is provided, characterized in that the hemodialysis device comprises, in sequence:

[0016] Blood infusion port;

[0017] Blood supply room;

[0018] Dialysis room;

[0019] Blood collection room; and

[0020] Blood outlet, including:

[0021] In the dialysis chamber, a plurality of semipermeable membranes for hemodialysis, as described above, are arranged parallel to each other in the direction from the blood supply chamber to the blood collection chamber.

[0022] The blood supply chamber and the blood collection chamber are fluidly connected only through a gap between two adjacent semipermeable membranes of the plurality of semipermeable membranes; and

[0023] The dialysis chamber has a dialysate inlet and a dialysate outlet on two walls perpendicular to the semipermeable membrane, and the dialysate inlet and the dialysate outlet are in fluid communication in the direction perpendicular to the semipermeable membrane. Attached Figure Description

[0024] Figure 1 A cross-sectional view of a semipermeable membrane for hemodialysis according to one embodiment of the present invention is shown; and

[0025] Figure 2 A cross-sectional view of a semipermeable membrane for hemodialysis according to another embodiment of the present invention is shown; and

[0026] Figure 3 A schematic diagram of a hemodialysis apparatus according to one embodiment of the present invention is shown. Detailed Implementation

[0027] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. It will be understood that other embodiments may be implemented without departing from the scope or spirit of the present invention. Therefore, the following detailed description is non-limiting.

[0028] Unless otherwise specified, all figures used in this specification and claims to indicate feature dimensions, quantities, and physical properties should be understood to be modified by the term "about" in all cases. Therefore, unless stated to the contrary, the numerical parameters listed in the foregoing specification and appended claims are approximations, and those skilled in the art can appropriately modify these approximations to obtain the desired characteristics using the teachings disclosed herein. The use of numerical ranges indicated by endpoints includes all numbers within that range and any range within that range; for example, 1 to 5 includes 1, 1.1, 1.3, 1.5, 2, 2.75, 3, 3.80, 4, and 5, etc.

[0029] As described above, this invention aims to address the problems existing in current hemodialysis semipermeable membranes. Current semipermeable membranes suffer from poor biocompatibility; some materials can activate the immune and coagulation systems, leading to inflammation and thrombosis risks, and protein adsorption affects dialysis efficiency. Furthermore, their removal efficiency for medium-molecular-weight substances is limited; traditional membranes are not ideal for removing medium-molecular-weight substances such as β2-microglobulin. Additionally, the membranes lack integrity and stability, making them prone to rupture and damage during long-term dialysis due to pressure changes and chemical corrosion. Increased usage leads to performance degradation, affecting dialysis accuracy. Therefore, developing semipermeable membranes with good biocompatibility, broader waste removal capabilities, and superior durability is of great significance.

[0030] According to one aspect of the present invention, a semipermeable membrane for hemodialysis is provided, characterized in that the semipermeable membrane comprises, in sequence:

[0031] First polyester fiber nonwoven fabric support layer;

[0032] First chitosan layer;

[0033] A porous polysulfone membrane, wherein the average pore size of the pores in the porous polysulfone membrane is in the range of 5 nm to 50 nm;

[0034] Second chitosan layer; and

[0035] Second polyester fiber nonwoven fabric support layer.

[0036] Figure 1 A cross-sectional view of a semipermeable membrane 100 for hemodialysis according to one embodiment of the present invention is shown. Specifically, the semipermeable membrane 100 sequentially comprises: a first polyester fiber nonwoven fabric support layer 1; a first chitosan layer 2; a porous polysulfone membrane 3; a second chitosan layer 4; and a second polyester fiber nonwoven fabric support layer 5.

[0037] Figure 2 A cross-sectional view of a semipermeable membrane 200 for hemodialysis according to another embodiment of the present invention is shown. Specifically, the semipermeable membrane 200 comprises, in sequence: a polyethylene glycol layer 6; a first polyester fiber nonwoven fabric support layer 1; a first chitosan layer 2; a porous polysulfone membrane 3; a second chitosan layer 4; a second polyester fiber nonwoven fabric support layer 5; and a polyethylene glycol layer 6.

[0038] The semipermeable membrane for hemodialysis of this invention has a unique layered structure, which sequentially includes a first polyester fiber nonwoven fabric support layer, a first chitosan layer, a porous polysulfone membrane, a second chitosan layer, and a second polyester fiber nonwoven fabric support layer.

[0039] The thickness of the first polyester fiber nonwoven support layer and the second polyester fiber nonwoven support layer is in the range of 50μm to 200μm, preferably 80μm to 15μm. Their main function is to provide a stable structural support for the entire semipermeable membrane, enhance the mechanical strength and durability of the semipermeable membrane, and ensure that the semipermeable membrane will not easily deform or be damaged during long-term hemodialysis.

[0040] The porous polysulfone membrane, as the core dialysis component of the semipermeable membrane, has an average pore size between 5 nm and 50 nm, preferably between 10 nm and 30 nm, and a thickness between 10 μm and 50 μm, preferably between 20 μm and 40 μm. These pore sizes allow for precise control of solute passage, enabling small molecules (such as urea and creatinine) and some medium-sized molecules (such as β2-microglobulin) to pass smoothly, while effectively blocking blood cells and large protein molecules, thus achieving selective blood purification. Preferably, the pores are through-pore structures extending throughout the entire membrane, which helps improve dialysis efficiency and allows waste products in the blood to diffuse more quickly into the dialysate.

[0041] The thickness of the first and second chitosan layers is between 1 μm and 10 μm, preferably between 3 μm and 5 μm. Chitosan has excellent adsorption properties and can specifically adsorb medium-molecular-weight substances (especially β2-microglobulins), thereby significantly enhancing the removal capacity of medium-molecular-weight waste and making up for the shortcomings of traditional semipermeable membranes in the removal of medium-molecular-weight substances.

[0042] Furthermore, a polyethylene glycol layer can be optionally disposed on the surface of the first polyester fiber nonwoven fabric support layer opposite to the first chitosan layer and / or on the surface of the second polyester fiber nonwoven fabric support layer opposite to the second chitosan layer. The thickness of the polyethylene glycol layer is in the range of 10 nm to 100 nm, preferably 30 nm to 50 nm. The presence of polyethylene glycol can effectively improve the biocompatibility of the semipermeable membrane, reduce adverse reactions such as coagulation and inflammation caused by blood contact with the membrane, and further improve the safety and effectiveness of the semipermeable membrane in hemodialysis applications.

[0043] According to another aspect of the present invention, a hemodialysis device is provided, characterized in that the hemodialysis device comprises, in sequence:

[0044] Blood infusion port;

[0045] Blood supply room;

[0046] Dialysis room;

[0047] Blood collection room; and

[0048] Blood outlet, including:

[0049] In the dialysis chamber, a plurality of semipermeable membranes for hemodialysis, as described above, are arranged parallel to each other in the direction from the blood supply chamber to the blood collection chamber.

[0050] The blood supply chamber and the blood collection chamber are fluidly connected only through a gap between two adjacent semipermeable membranes among the plurality of semipermeable membranes; and

[0051] The dialysis chamber has a dialysate inlet and a dialysate outlet on two walls perpendicular to the semipermeable membrane, and the dialysate inlet and the dialysate outlet are in fluid communication in the direction perpendicular to the semipermeable membrane.

[0052] Figure 3 A schematic diagram of a hemodialysis apparatus 300 according to one embodiment of the present invention is shown. Specifically, the hemodialysis apparatus 300 sequentially includes: a blood inlet 7; a blood supply chamber 8; a dialysis chamber 9; a blood collection chamber 10; and a blood outlet 11, wherein: in the dialysis chamber 9, a plurality of semipermeable membranes 12 for hemodialysis are arranged parallel to each other in the direction from the blood supply chamber 8 to the blood collection chamber 10; the blood supply chamber 8 and the blood collection chamber 10 are fluidly connected only through a gap 13 between two adjacent semipermeable membranes 12; and the dialysis chamber 9 has a dialysate inlet 14 and a dialysate outlet 15 on two walls in a direction perpendicular to the semipermeable membranes 12, and the dialysate inlet 14 and the dialysate outlet 15 are fluidly connected in a direction perpendicular to the semipermeable membranes 12.

[0053] Specifically, the hemodialysis device of this utility model mainly consists of a blood inlet, a blood supply chamber, a dialysis chamber, a blood collection chamber, and a blood outlet.

[0054] The blood inlet is used to introduce the patient's blood into the hemodialysis device. Its design should ensure that the blood can flow in smoothly and steadily, and it should have good sealing properties to prevent blood leakage.

[0055] The blood supply room serves to temporarily store and supply blood, ensuring that the blood maintains a certain pressure and flow stability before entering the dialysis room, thus providing favorable conditions for the subsequent dialysis process.

[0056] The dialysis chamber is a crucial area for hemodialysis. Within this chamber, multiple semi-permeable membranes used for hemodialysis are arranged parallel to each other in the direction from the blood supply chamber to the blood collection chamber. The gaps between adjacent semi-permeable membranes are in the range of 500 nm to 10 μm, preferably 1 μm to 5 μm. This gap design ensures both uniform and orderly blood flow between adjacent semi-permeable membranes and sufficient contact area and exchange space between the blood and dialysate, thereby achieving efficient dialysis. The dialysis chamber has a dialysate inlet and a dialysate outlet on two walls perpendicular to the semi-permeable membranes. The dialysate inlet introduces the prepared dialysate into the dialysis chamber, while the dialysate outlet discharges the used dialysate. By rationally controlling the flow rate and direction of the dialysate, sufficient circulation of the dialysate within the dialysis chamber and adequate exchange of substances with the blood can be ensured.

[0057] The blood collection chamber is used to collect dialysis blood, gather it, and maintain a certain pressure so that it can be smoothly returned to the patient through the blood outlet.

[0058] The blood output port is responsible for safely and stably returning the purified blood to the patient. Its structure and materials must meet biocompatibility and sealing requirements to ensure a safe and reliable blood return process. The entire hemodialysis device can be designed in common shapes such as cylinders, cuboids, or cubes to adapt to different usage scenarios and installation requirements. At the same time, it must ensure tight and reasonable connections between components and an optimized internal structural layout to achieve efficient and stable hemodialysis functionality.

[0059] According to the technical solution of this utility model, the materials constituting the first polyester fiber nonwoven support layer, the first chitosan layer, the porous polysulfone membrane, the second chitosan layer, the second polyester fiber nonwoven support layer, and the optional polyethylene glycol layer are all commercially available materials, or these materials can be prepared by known methods in the prior art. For example, the first polyester fiber nonwoven support layer and the second polyester fiber nonwoven support layer can be made of 3M Tegaderm. TM This invention relates to a series of nonwoven fabrics and Maipu Medical polyester nonwoven fabric products. The chitosan used in the first and second chitosan layers can be from Qingdao Bozhi Huili Biotechnology Co., Ltd. The polysulfone material used in the porous polysulfone membrane can be from BASF's Ultrason series. The ethylene glycol raw material used in the ethylene glycol layer can be from Dow Chemical's CARBOWAX polyethylene glycol series. This invention is not limited to these products.

[0060] In addition to the components discussed above, the hemodialysis device of this invention may also include the following optional components:

[0061] 1. Pressure monitoring device:

[0062] Blood pressure monitor: can be installed in different locations such as the blood inlet, blood supply room, dialysis room, and blood collection room to monitor blood pressure changes in real time during dialysis; and / or

[0063] Dialysis fluid side pressure monitor: Located near the dialysate inlet and dialysate outlet, it monitors the pressure of the dialysate in the dialysis chamber.

[0064] 2. Flow monitoring and regulation device

[0065] Blood flow monitor and regulator: Used to monitor and regulate the blood flow rate within the dialysis unit. The blood flow rate is typically controlled at 200-300 ml / min; and / or

[0066] Dialysis fluid flow monitor and regulator: Monitors and controls the flow rate of the dialysis fluid. The flow rate is typically 500-800 ml / min.

[0067] 3. Temperature control system

[0068] Dialysis fluid temperature regulator: Maintains the dialysate within a suitable temperature range, typically 36-37°C; and / or

[0069] Blood temperature monitor: It can help monitor the temperature changes of blood during dialysis.

[0070] 4. Safety alarm device

[0071] Pressure Anomaly Alarm: When the pressure on the blood side or dialysate side exceeds the preset safety range, an alarm signal is immediately triggered; and / or

[0072] Abnormal flow alarm: If the blood flow or dialysate flow deviates from the normal set value by a certain range, the alarm device will be activated; and / or

[0073] Temperature anomaly alarm: The temperature anomaly alarm function will be activated if the dialysate temperature exceeds the suitable range of 36-37℃.

[0074] 5. Air detection and removal device

[0075] Air detector: Installed in the blood circuit, it can detect whether air is mixed in with the blood; and / or

[0076] Air eliminators (such as bubble traps): These are usually located near the blood outlet. When an air detector detects air, the air is guided into the bubble trap. The bubble trap uses a special structure (such as a filter or spiral channel) to collect the air at the top, while the blood flows safely back into the patient's body from the bottom, thus effectively removing air and ensuring patient safety.

[0077] The semi-permeable membrane and hemodialysis device for hemodialysis according to this invention can be prepared and used by the following method. In the preparation of the semi-permeable membrane, the materials used for all the laminated structures (including the first polyester fiber nonwoven support layer, the first chitosan layer, the porous polysulfone membrane, the second chitosan layer, the second polyester fiber nonwoven support layer, and optionally the polyethylene glycol layer) are commercially available or prepared according to methods well known in the chemical field. The following are merely illustrative examples of the preparation and use of the semi-permeable membrane and hemodialysis device; however, this invention is by no means limited thereto. Those skilled in the art can select suitable known materials and process steps based on known process flows.

[0078] Preparation of semipermeable membrane

[0079] Select appropriate specifications for first and second polyester fiber nonwoven fabrics (e.g., 3MTegaderm). TM A series of nonwoven fabrics are used as the support layer material, with a thickness ranging from 50μm to 200μm, ensuring good mechanical strength and flexibility, and providing stable structural support for the entire semi-permeable membrane. For example, a 100μm thick polyester fiber nonwoven fabric can be selected, whose fibers are fine and evenly distributed, and can effectively withstand pressure changes during dialysis.

[0080] Prepare porous polysulfone membrane materials with an average pore size controlled between 5 nm and 50 nm and a thickness ranging from 10 μm to 50 μm. Porous polysulfone membranes are commercially available or can be prepared using phase inversion methods well-known in the chemical field. For example, polysulfone (e.g., Ultrason series polysulfone products from BASF, Germany) is dissolved in a suitable solvent (such as N,N-dimethylacetamide (DMAc)), a pore-forming agent (such as nitrogen or polyvinylpyrrolidone (PVP)) is added to form a casting solution, which is then cast through a specific mold and dried in a coagulation bath to evaporate the solvent, thereby solidifying and forming a polysulfone membrane with a uniform pore structure to achieve effective sieving of solutes of different sizes.

[0081] A first and second chitosan layer, with a thickness between 1 μm and 10 μm, are prepared using chitosan raw materials (e.g., chitosan products from Qingdao Bozhi Huili Biotechnology Co., Ltd.). Chitosan can be dissolved in dilute acetic acid solution to prepare a chitosan solution of a certain concentration. This solution is then coated onto the corresponding membrane surface by methods such as impregnation, spraying, or spin coating. After drying and evaporation of the solvent, a chitosan layer is formed, which is used to adsorb medium-molecular-weight substances (especially β2-microglobulins).

[0082] If a polyethylene glycol (PEG) layer is required, prepare PEG raw materials (e.g., Dow Chemical's CARBOWAX PEG series products), with the molecular weight selected according to actual needs. The PEG layer thickness ranges from 10 nm to 100 nm. PEG can be attached to the surface of the polyester nonwoven fabric support layer through well-known physical adsorption or solvent coating methods to improve the biocompatibility of the semi-permeable membrane.

[0083] Layered structure construction:

[0084] First, the first polyester fiber nonwoven fabric support layer is laid flat, and a first chitosan layer solution is uniformly coated on one side surface. The thickness and uniformity of the chitosan layer are ensured by controlling the coating amount and drying conditions. For example, after coating by impregnation, it is dried in an oven at 60°C for 30 minutes to ensure that the chitosan layer adheres tightly to the support layer.

[0085] Next, the prepared porous polysulfone membrane is carefully bonded to the first chitosan layer, ensuring a tight bond without bubbles or wrinkles. Hot pressing or vacuum bonding can be used to improve the tightness of the bond and ensure the overall integrity of the semi-permeable membrane.

[0086] Then, a second chitosan layer is coated on the other side of the porous polysulfone membrane. The uniformity of the coating and the thickness control must be ensured. The operation method is similar to that of the first chitosan layer.

[0087] Finally, the second polyester fiber nonwoven fabric support layer is covered on the second chitosan layer, and then hot-pressed or otherwise appropriately treated to firmly bond the layers together, forming a complete semi-permeable membrane structure for hemodialysis.

[0088] Assembly of a hemodialysis device:

[0089] Prepare or select blood inlet, blood supply chamber, dialysis chamber, blood collection chamber and blood outlet components that meet the requirements. The materials of these components should have good chemical stability and biocompatibility, such as medical-grade polycarbonate or polypropylene.

[0090] Prepare multiple semipermeable membranes prepared above for hemodialysis, ensuring that the size of the semipermeable membranes is within the range of 20 cm to 50 cm in the direction from the blood supply chamber to the blood collection chamber, and that the gap between adjacent semipermeable membranes is between 500 nm and 10 μm, so as to ensure smooth blood flow and effective dialysis during the dialysis process.

[0091] Assembly of the dialysis chamber:

[0092] The dialysis chamber is designed as a cavity structure with a certain space. A dialysate inlet and outlet are respectively located on two walls perpendicular to the semipermeable membrane. The positions of the inlet and outlet should be rationally distributed to ensure that the dialysate flows evenly across the surface of the semipermeable membrane. For example, the dialysate inlet can be located on one side of the bottom of the dialysis chamber, and the dialysate outlet can be located on the opposite side of the top, allowing for good convection of the dialysate within the dialysis chamber.

[0093] In the dialysis chamber, multiple semipermeable membranes are fixedly installed parallel to each other in the direction from the blood supply chamber to the blood collection chamber. The semipermeable membranes can be fixed by means of slots or clamps to ensure that the gaps between the semipermeable membranes are uniform and consistent. Adjacent semipermeable membranes are fluidly connected only through gaps, allowing blood to flow through each semipermeable membrane sequentially for dialysis.

[0094] Connect one end of the blood supply room to the dialysis room. The connection should be airtight and leak-free, using methods such as sealing rings or welding. Connect the blood inlet to the blood supply room to ensure smooth blood flow.

[0095] Connect the blood collection chamber to the other end of the dialysis chamber, ensuring the connection is airtight. Connect the blood outlet to the blood collection chamber to allow dialysis blood to be safely returned to the patient.

[0096] How to use a hemodialysis device

[0097] The assembled hemodialysis device undergoes strict disinfection, which can be achieved by high-temperature and high-pressure steam sterilization or immersion in chemical disinfectants, to ensure that there are no bacteria, viruses, or other microorganisms remaining inside the device and to prevent the risk of infection.

[0098] Prepare the dialysate according to the prescribed formula and concentration, and inject it into the dialysis chamber through the dialysate inlet until the dialysis chamber is full and reaches the predetermined liquid level. At the same time, check whether the dialysate temperature, pH value and other parameters meet the dialysis requirements. Generally, the dialysate temperature is controlled at 36-37℃ and the pH value is between 7.0 and 7.4.

[0099] The process of hemodialysis:

[0100] Blood is drawn from the patient's body through a vascular access (such as an arteriovenous fistula or central venous catheter) and introduced into the blood supply chamber through a blood inlet at an appropriate flow rate (generally 200-300 ml / min).

[0101] After initial distribution in the storage chamber, the blood flows sequentially through multiple semipermeable membranes in the dialysis chamber. During dialysis, small molecules (such as urea and creatinine) and medium molecules (such as β2-microglobulin) in the blood diffuse through the semipermeable membranes into the dialysate based on their concentration gradient. Simultaneously, certain beneficial components in the dialysate (such as bicarbonate ions) can also diffuse into the blood, maintaining the blood's acid-base balance. During dialysis, the pressure difference between the blood and dialysate must be closely monitored. By adjusting the dialysis machine parameters, the pressure difference should be controlled within a safe range (generally not exceeding 50 mmHg) to prevent semipermeable membrane rupture.

[0102] After dialysis, the blood is collected in the blood collection chamber and then returned to the patient at a stable flow rate through the blood outlet. The duration of the entire dialysis process depends on the patient's condition and dialysis needs, and generally lasts 3-5 hours.

[0103] After dialysis, the remaining blood and dialysate in the dialysis device are drained, the device is rinsed with saline to remove any residue, and then it is disinfected again for the next use.

[0104] The following list of embodiments further illustrates various exemplary embodiments of the present invention, which should not be construed as unduly limiting the present invention:

[0105] Specific implementation scheme 1 is a semipermeable membrane for hemodialysis, characterized in that the semipermeable membrane comprises, in sequence:

[0106] First polyester fiber nonwoven fabric support layer;

[0107] First chitosan layer;

[0108] A porous polysulfone membrane, wherein the average pore size of the pores in the porous polysulfone membrane is in the range of 5 nm to 50 nm;

[0109] Second chitosan layer; and

[0110] Second polyester fiber nonwoven fabric support layer.

[0111] Specific implementation scheme 2 is a semipermeable membrane for hemodialysis as described in specific implementation scheme 11, characterized in that the thickness of the first polyester fiber nonwoven support layer and the second polyester fiber nonwoven support layer is in the range of 50μm to 200μm.

[0112] Specific implementation scheme 3 is a semipermeable membrane for hemodialysis as described in specific implementation scheme 1, characterized in that the thickness of the porous polysulfone membrane is in the range of 10 μm to 50 μm.

[0113] Specific implementation scheme 4 is a semipermeable membrane for hemodialysis as described in specific implementation scheme 1, characterized in that the pores in the porous polysulfone membrane are through-holes extending through the porous polysulfone membrane.

[0114] Specific implementation scheme 5 is a semipermeable membrane for hemodialysis as described in specific implementation scheme 1, characterized in that the thickness of the first chitosan layer and the second chitosan layer is in the range of 1 μm to 10 μm.

[0115] Specific implementation scheme 6 is a semipermeable membrane for hemodialysis as described in specific implementation scheme 1, characterized in that:

[0116] A polyethylene glycol layer is disposed on the surface of the first polyester fiber nonwoven fabric support layer opposite to the first chitosan layer; and / or

[0117] A polyethylene glycol layer is disposed on the surface of the second polyester fiber nonwoven fabric support layer opposite to the second chitosan layer.

[0118] Specific implementation scheme 7 is a semipermeable membrane for hemodialysis as described in specific implementation scheme 6, characterized in that the thickness of the polyethylene glycol layer is in the range of 10 nm to 100 nm.

[0119] Specific implementation scheme 8 is a hemodialysis device, characterized in that the hemodialysis device comprises, in sequence:

[0120] Blood infusion port;

[0121] Blood supply room;

[0122] Dialysis room;

[0123] Blood collection room; and

[0124] Blood outlet, including:

[0125] In the dialysis chamber, a plurality of semipermeable membranes for hemodialysis, according to any one of embodiments 1 to 7, are arranged parallel to each other in the direction from the blood supply chamber to the blood collection chamber.

[0126] The blood supply chamber and the blood collection chamber are fluidly connected only through a gap between two adjacent semipermeable membranes of the plurality of semipermeable membranes; and

[0127] The dialysis chamber has a dialysate inlet and a dialysate outlet on two walls perpendicular to the semipermeable membrane.

[0128] Specific implementation scheme 9 is a hemodialysis device according to specific implementation scheme 8, characterized in that the gap between two adjacent semipermeable membranes among the plurality of semipermeable membranes is in the range of 500nm to 10μm.

[0129] Specific implementation scheme 10 is a hemodialysis device according to specific implementation scheme 8, characterized in that the size of the semipermeable membrane in the direction from the blood supply chamber to the blood collection chamber is in the range of 20cm to 50cm.

[0130] Specific implementation scheme 11 is a hemodialysis device according to specific implementation scheme 8, characterized in that the hemodialysis device is in the shape of a cylinder, cuboid, or cube.

[0131] Compared with the semipermeable membranes and hemodialysis devices in the prior art, the advantages of the semipermeable membranes and hemodialysis devices according to this invention are as follows:

[0132] 1. Biocompatibility: The semipermeable membrane of this invention improves biocompatibility by adding a chitosan layer and an optional polyethylene glycol layer, reducing adverse reactions such as coagulation and inflammation caused by blood contact with the membrane, and improving the safety and effectiveness of the semipermeable membrane in hemodialysis applications.

[0133] 2. Waste removal capability: The average pore size of the porous polysulfone membrane is in the range of 5nm to 50nm, which enables the semipermeable membrane to effectively remove not only small molecules (such as urea and creatinine) but also medium molecules (such as β2-microglobulin), thus providing a wider range of waste removal capabilities.

[0134] 3. Durability: The first and second polyester fiber nonwoven support layers provide a solid structural support, enhancing the mechanical strength and durability of the semipermeable membrane and ensuring that the semipermeable membrane will not easily deform or be damaged during long-term hemodialysis.

[0135] 4. Structural optimization: The layered structure design of the semipermeable membrane, including a polyester fiber nonwoven support layer, a chitosan layer, and a porous polysulfone membrane, enables the semipermeable membrane to maintain good dialysis efficiency while also having better stability and durability.

[0136] 5. Dialysis device design: The design of the hemodialysis device allows multiple semipermeable membranes to be arranged in parallel in the dialysis chamber. Fluid communication is achieved through the gaps between adjacent semipermeable membranes, ensuring smooth blood flow and effective dialysis during the dialysis process.

[0137] 6. Fluid connectivity: The blood supply chamber and the blood collection chamber are fluidly connected only through the gap between the semipermeable membranes. This design ensures that the blood flows evenly and orderly between adjacent semipermeable membranes, and also ensures that there is sufficient contact area and exchange space between the blood and the dialysate, so as to achieve a high-efficiency dialysis effect.

[0138] 7. Size and gap control: Size control of the semipermeable membrane in the direction from the blood supply chamber to the blood collection chamber, as well as gap control between adjacent semipermeable membranes, helps to optimize dialysis efficiency and blood flow.

[0139] Obviously, those skilled in the art can make various modifications and variations to this disclosure without departing from the spirit and scope of this disclosure. Therefore, if such modifications and variations fall within the scope of the claims of this utility model and their equivalents, this disclosure is also intended to include such modifications and variations.

Claims

1. A semipermeable membrane for hemodialysis, characterized by, The semipermeable membrane comprises, in order: a first polyester fiber nonwoven support layer; a first chitosan layer; a porous polysulfone membrane, pores in the porous polysulfone membrane having an average pore diameter in the range of 5 nm to 50 nm; a second chitosan layer; and a second polyester fiber nonwoven support layer.

2. The semipermeable membrane for hemodialysis according to claim 1, wherein The first polyester fiber nonwoven support layer and the second polyester fiber nonwoven support layer have a thickness in the range of 50 μm to 200 μm.

3. The semipermeable membrane for hemodialysis according to claim 1, wherein The porous polysulfone membrane has a thickness in the range of 10 μm to 50 μm.

4. The semipermeable membrane for hemodialysis according to claim 1, wherein The pores in the porous polysulfone membrane are through-holes extending through the porous polysulfone membrane.

5. The semipermeable membrane for hemodialysis according to claim 1, wherein The first chitosan layer and the second chitosan layer have a thickness in the range of 1 μm to 10 μm.

6. The semipermeable membrane for hemodialysis according to claim 1, wherein: a polyethylene glycol layer is provided on a surface of the first polyester fiber nonwoven support layer opposite the first chitosan layer; and / or a polyethylene glycol layer is provided on a surface of the second polyester fiber nonwoven support layer opposite the second chitosan layer.

7. The semipermeable membrane for hemodialysis according to claim 6, wherein The polyethylene glycol layer has a thickness in the range of 10 nm to 100 nm.

8. A hemodialysis device, characterized by The hemodialysis device comprises, in order: a blood input port; a blood supply chamber; a dialysis chamber; a blood convergence chamber; and a blood output port, wherein: a plurality of the semipermeable membranes for hemodialysis according to any one of claims 1 to 7 are provided in the dialysis chamber in parallel with each other in a direction from the blood supply chamber to the blood convergence chamber; the blood supply chamber and the blood convergence chamber are in fluid communication only through a gap between adjacent two of the semipermeable membranes; and the dialysis chamber has a dialysate inlet and a dialysate outlet on two walls in a direction perpendicular to the semipermeable membranes, respectively, and the dialysate inlet and the dialysate outlet are in fluid communication in the direction perpendicular to the semipermeable membranes.

9. The hemodialysis device of claim 8, wherein, The gap between adjacent two of the semipermeable membranes is in the range of 1 μm to 10 μm.

10. The hemodialysis device of claim 8, wherein, A dimension of the semipermeable membrane in a direction from the blood supply chamber to the blood convergence chamber is in the range of 20 cm to 50 cm.

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