A method for detecting blood chamber pressure drop in an HD single-pump machine and the HD single-pump machine itself.

Abstract

This invention relates to a method for detecting blood chamber pressure drop in a single-pump hemodialysis machine (HD), and to an HD single-pump hemodialysis machine. The HD single-pump hemodialysis machine includes a dialyzer, a dialysate circuit, and a blood circuit. The dialyzer includes a semipermeable membrane. The dialysate circuit flows through the outer side of the semipermeable membrane, and the inner side of the semipermeable membrane is the blood chamber. The blood circuit flows through the blood chamber. The detection method includes the following steps: when the dialyzer is performing hemodialysis, the dialysate pressure outside the semipermeable membrane is set equal to the blood chamber pressure inside the semipermeable membrane; the return pressure of the dialysate circuit, the blood chamber outlet pressure, the dialysis flow rate, and the dialysate pressure difference coefficient are obtained; the blood chamber pressure drop is calculated based on the return pressure, the blood chamber outlet pressure, the dialysis flow rate, and the dialysate pressure difference coefficient, and the blood chamber pressure drop is used as the detection result. This invention can detect the blood chamber pressure drop using only existing equipment conditions, without requiring an additional pressure sensor at the blood chamber inlet of the dialyzer, thus exhibiting outstanding practicality.

Description

Technical Field

[0001] This invention relates to the field of hemodialysis technology, and in particular to a method for detecting blood chamber pressure drop in an HD single-pump machine and the HD single-pump machine itself. Background Technology

[0002] Hemodialysis is a renal replacement therapy system that draws blood out of the body and purifies it before returning it to the body through a dialyzer containing a semipermeable membrane. It utilizes the concentration gradient, osmotic pressure gradient, and water pressure gradient between the blood and dialysate flowing through the semipermeable membrane, as well as the properties of the membrane itself, to remove metabolic waste and excess water from the blood through diffusion, convection, and adsorption, thus resolving electrolyte imbalances and acid-base disturbances in the patient's blood.

[0003] Currently, different types of hemodialysis methods and instruments are needed for patients with different conditions. These include hemodialysis (HD) using a single-pump machine, which is mainly used to remove small molecule toxins and is suitable for the initial stage of hemodialysis; and hemodiafiltration (HDF) using a dual-pump machine, which mainly removes medium molecule toxins and is suitable for the middle stage of hemodialysis. Because the dual-pump HDF machine is less effective at removing small molecule toxins than the single-pump HD machine, and because the medical treatment courses corresponding to the dual-pump HDF machine and the single-pump HD machine are different, the two cannot be used interchangeably.

[0004] Existing HDF dual-pump machines have pressure sensors at the dialyzer blood chamber inlet and venous pressure sensors at the dialyzer blood chamber outlet, allowing for convenient detection of blood chamber pressure drop by comparing the inlet and outlet pressure values. Blood chamber pressure drop refers to the pressure difference between the blood inside and outside the blood chamber during normal operation of the hemodialysis equipment. Simply put, it's the resistance blood must overcome as it passes through the hemodialysis equipment during dialysis; it can also be understood as the internal resistance of the dialyzer. The magnitude of the blood chamber pressure drop directly affects the dialysis effect and the impact on the patient during dialysis. However, existing HD single-pump machines lack a pressure sensor at the dialyzer blood chamber inlet. Therefore, these machines cannot detect blood chamber pressure drop, preventing healthcare professionals from using it to monitor the patient's coagulation and blood permeability during hemodialysis (HD). Summary of the Invention

[0005] The purpose of this invention is to provide a method for detecting blood chamber pressure drop in HD single-pump dialyzers, solving the technical problem that HD single-pump dialyzers cannot detect blood chamber pressure drop when they lack a pressure sensor at the inlet of the dialyzer blood chamber.

[0006] To achieve the above objectives, the first aspect of the present invention provides a method for detecting blood chamber pressure drop in a single-pump HD dialyzer. The HD dialyzer includes a dialyzer, a dialysate circuit, and a blood circuit. The dialyzer includes a semipermeable membrane. The dialysate circuit flows through the outer side of the semipermeable membrane, and the inner side of the semipermeable membrane is a blood chamber. The blood circuit flows through the blood chamber. The method includes the following steps:

[0007] When the dialyzer performs hemodialysis, the dialysate pressure outside the semipermeable membrane is set equal to the blood chamber pressure inside the semipermeable membrane; the return pressure, blood chamber outlet pressure, dialysis flow rate, and dialysate pressure difference coefficient of the dialysate circuit are obtained; the blood chamber pressure drop is calculated based on the return pressure, blood chamber outlet pressure, dialysis flow rate, and dialysate pressure difference coefficient, and the blood chamber pressure drop is used as the detection result.

[0008] The aforementioned method for detecting blood chamber pressure drop in a single-pump dialyzer involves setting the dialysate pressure outside the semipermeable membrane to equal the blood chamber pressure inside the membrane during hemodialysis. Based on this condition, the invention obtains the return pressure, dialysis flow rate, and dialysate pressure difference coefficient of the dialysate circuit outside the membrane, and the outlet pressure of the blood chamber inside the membrane. By using the data from outside the membrane, the blood chamber pressure drop inside the membrane is indirectly obtained. This solves the technical problem of existing single-pump dialyzers being unable to detect blood chamber pressure drop, even when the single-pump dialyzer lacks a pressure sensor at the blood chamber inlet and cannot obtain the inlet pressure value. Furthermore, this invention utilizes only the existing equipment of the single-pump dialyzer to detect blood chamber pressure drop, eliminating the need for an additional pressure sensor at the blood chamber inlet, making it easy to promote and use in the field and possessing outstanding practicality.

[0009] It should be noted that, due to the additional pressure sensor installed at the inlet of the dialyzer blood chamber of the HD single-pump machine, obtaining the pressure value at the blood chamber inlet faces technical difficulties in actual operation, which may lead to undesirable technical results. To further illustrate this, this application provides supplementary explanations of the difficulties encountered in the actual operation of the technical means of "adding an additional pressure sensor at the inlet of the dialyzer blood chamber of the HD single-pump machine" through the following content.

[0010] First, it is worth noting that in existing HD single-pump machines, the dialyzer blood chamber inlet also has a blood pump. This blood pump is used to regulate the pressure in the blood circuit and propel the blood to circulate within it. Specifically, after arterial blood flows into the blood circuit through the arterial puncture needle, it is pressurized by the blood pump and pumped from the blood chamber inlet into the dialyzer blood chamber. After completing the hemodialysis process in the dialyzer blood chamber, it flows out from the blood chamber outlet and returns to the patient's vein via the blood circuit and venous puncture needle. The mechanical motion of the blood pump introducing the blood fluid introduces periodic fluctuations and vibrations. Adding an extra pressure sensor at the blood chamber inlet will be affected by this mechanical motion, impacting the stability of the pressure sensor's measurement and causing errors in the measured data. Furthermore, the lifespan of the pressure sensor will be affected, and it may even be damaged, if it operates under these conditions for an extended period.

[0011] Secondly, adding an additional pressure sensor to the blood chamber inlet of the existing HD single-pump machine requires a redesign of the corresponding blood tubing connection structure, which may alter the hydrodynamic characteristics of blood flow in the blood circuit, negatively impacting the hemodialysis function of the HD single-pump machine. Furthermore, the added pressure sensor requires regular calibration and maintenance, increasing the complexity of the equipment and reducing the practicality of the HD single-pump machine itself.

[0012] Finally, because existing HDF dual-pump machines are equipped with additional blood pumps—one for propelling blood circulation in the blood circuit and the other for controlling the injection of replacement fluid—HDF dual-pump machines have a larger device layout and longer tubing compared to HD single-pump machines, allowing for the placement of a pressure sensor at the blood chamber inlet. In contrast, existing HD single-pump machines, requiring only one pump, have a more streamlined overall structure and more concentrated tubing, lacking the space to accommodate an additional pressure sensor at the blood chamber inlet. Forcibly adding a pressure sensor to the blood chamber inlet of an existing HD single-pump dialyzer could compromise its streamlined structure, negatively impacting its simple design and ease of operation, rendering it unsuitable for the initial stages of hemodialysis.

[0013] It should be understood that in the field of medical device technology, the positive technical effects of hemodialysis equipment are not simply determined by factors such as equipment size or the number of blood pumps. For patients with different conditions and different treatment courses, the correct use of corresponding hemodialysis methods and instruments is necessary to achieve the desired technical effects. Specifically, the HDF dual-pump machine is suitable for hemodialysis filtration, primarily removing medium-molecular-weight toxins, and is used in the middle and late stages of hemodialysis. Although the HDF dual-pump machine has an additional blood pump and pressure sensor compared to the HD single-pump machine, for patients in the initial stage of hemodialysis, the HDF dual-pump machine is less effective at removing small-molecular-weight toxins than the HD single-pump machine. Furthermore, the complex functionality of the HDF dual-pump machine may pose additional risks to patients in the initial stage of hemodialysis. For example, the excessively high blood flow rate brought by the HDF dual-pump machine at this stage, and the injection of replacement fluid into the blood circuit by the dual-pump machine, may also cause fluid imbalance in patients at this time. Therefore, even though the HDF dual-pump machine has a pressure sensor at the dialyzer blood chamber inlet and a venous pressure sensor at the dialyzer blood chamber outlet, which can conveniently detect the pressure drop in the dialyzer blood chamber by comparing the pressure values ​​at the blood chamber inlet and outlet, it cannot replace the HD single-pump machine for the initial course of hemodialysis treatment.

[0014] In summary, existing HD single-pump dialyzers are irreplaceable for their applicable medical procedures. Adding an additional pressure sensor to existing HD single-pump dialyzers is not only difficult to implement and yields unsatisfactory results, but may also disrupt the original streamlined structure of the existing HD single-pump dialyzer, leading to adverse technical effects. Therefore, this invention utilizes only the existing equipment of the HD single-pump dialyzer to detect blood chamber pressure drop, eliminating the need for an additional pressure sensor at the dialyzer blood chamber inlet. This makes it easy to promote and use in the field, demonstrating outstanding practicality.

[0015] In one possible implementation, the specific calculation formula for the blood chamber pressure drop based on the return fluid pressure value, the blood chamber outlet pressure value, the dialysis flow rate, and the dialysate pressure difference coefficient is as follows: Formula 1:

[0016] PB = (PDo + PDo + K*F) d ) - 2PV (Equation 1)

[0017] Wherein, PB is the blood chamber pressure drop, PV is the blood chamber outlet pressure, PDo is the return fluid pressure, K is the dialysate pressure differential coefficient, and F... d The dialysis flow rate is [value missing].

[0018] It should be noted that the pressure drop in the blood chamber specifically refers to the pressure at the inlet of the blood chamber minus the pressure at the outlet of the blood chamber. In the medical field, the pressure at the inlet of the blood chamber is also known as the pre-filter pressure, and the pressure at the outlet of the blood chamber is also known as the venous pressure. Therefore, the pressure drop in the dialyzer blood chamber can also be described as equal to the pre-filter pressure minus the venous pressure, which can be expressed by the following formula 2:

[0019] PB = PA - PV (Equation 2)

[0020] Wherein, PB is the pressure drop of the blood chamber, PV is the pressure value at the outlet of the blood chamber, and PA is the pressure value at the inlet of the blood chamber.

[0021] For the blood circuit flowing through the blood chamber, due to resistance during blood flow, the pressure of blood exiting the dialyzer blood chamber is lower than the pressure entering the dialyzer blood chamber; that is, the pressure at the blood chamber outlet is lower than the pressure at the blood chamber inlet, and this pressure decrease is linear. Therefore, the blood chamber pressure inside the dialyzer semipermeable membrane is equal to the average of the blood chamber inlet pressure and the blood chamber outlet pressure, which can be expressed as Equation 3:

[0022] Pb = (PA + PV) / 2 (Equation 3)

[0023] Wherein, Pb is the blood chamber pressure value, PA is the blood chamber inlet pressure value, and PV is the blood chamber outlet pressure value.

[0024] It should also be noted that in the medical field, the end of the dialysate circuit in a HD single-pump machine that flows into the dialyzer has a supply valve, which can be called the supply end, and the end of the dialysate circuit that flows out of the dialyzer has a return valve, which can be called the return end. The pressure values ​​at the supply end and the return end have the mathematical relationship shown in Equation 4 below:

[0025] Pn = PDi - PDo = K*F d (Equation 4)

[0026] Wherein, Pn is the pressure difference between the dialysate flowing into and out of the dialyzer, i.e., the pressure difference between the supply end and the return end; PDi is the pressure value at the supply end; PDo is the pressure value at the return end; K is the dialysate pressure difference coefficient; and F... d The dialysis flow rate is [value missing].

[0027] Similarly, for the dialysate circuit flowing outside the semipermeable membrane, since there is also resistance during the flow of the dialysate in the circuit, the pressure of the dialysate flowing out of the dialyzer will be less than the pressure flowing into the dialyzer. That is, the pressure at the return end of the dialysate circuit is less than the pressure at the supply end of the dialysate circuit, and this pressure decrease is a linear decrease. Therefore, the dialysate pressure outside the semipermeable membrane of the dialyzer is equal to the average of the supply end pressure and the return end pressure, which can be expressed as Equation 5:

[0028] Pd = (PDi + PDo) / 2 (Formula 5)

[0029] Wherein, Pd is the dialysate pressure outside the semipermeable membrane, PDi is the supply pressure, and PDo is the return pressure.

[0030] In this implementation, by setting the dialysate pressure Pd outside the semipermeable membrane to be equal to the blood chamber pressure Pb inside the semipermeable membrane, the physical quantities in the HD single-pump machine at this moment have the physical relationship described in Equation 6:

[0031] Pb = ( PA + PV ) / 2 = Pd = ( PDi + PDo ) / 2 (Equation 6)

[0032] Wherein, Pb is the blood chamber pressure value, PA is the blood chamber inlet pressure value, PV is the blood chamber outlet pressure value, Pd is the dialysate pressure value outside the semipermeable membrane, PDi is the supply pressure value, and PDo is the return pressure value. Based on this, by combining the physical relationships of Equations 6, 4, and 2, the physical calculation formula shown in Equation 1 can be obtained. Through the above technical means, this implementation method can detect the blood chamber pressure drop at the current moment without obtaining the blood chamber inlet pressure value, solving the technical problem that existing HD single-pump machines cannot detect the blood chamber pressure drop, and eliminating the need to install an additional pressure sensor at the dialyzer blood chamber inlet, making it easy to promote and use in this field.

[0033] In one possible implementation, the HD single-pump machine further includes an ultrafiltration pump located at the return end of the dialysate circuit. The step of ensuring that the dialysate pressure outside the semipermeable membrane equals the blood chamber pressure inside the semipermeable membrane during hemodialysis includes: controlling the ultrafiltration pump to pause operation, thereby ensuring that the dialysate pressure outside the semipermeable membrane equals the blood chamber pressure inside the semipermeable membrane.

[0034] In this implementation, the ultrafiltration pump is used to regulate the pressure in the dialysate circuit, driving the dialysate to circulate within the circuit. When the ultrafiltration pump stops operating, the dialysate pressure in the dialysate circuit is no longer affected by the additional pressure applied by the ultrafiltration pump, but only by the static pressure. At this time, based on the physical characteristics of the semipermeable membrane, the dialysate pressure outside the semipermeable membrane will gradually become consistent with the blood chamber pressure inside the semipermeable membrane, eventually achieving a dynamic pressure balance between the inside and outside of the semipermeable membrane, thus making the dialysate pressure outside the semipermeable membrane equal to the blood chamber pressure inside the semipermeable membrane.

[0035] In one possible implementation, the step of calculating the blood chamber pressure drop based on the return fluid pressure value, the blood chamber outlet pressure value, the dialysis flow rate, and the dialysate pressure difference coefficient, and using the blood chamber pressure drop as the detection result, further includes: controlling the ultrafiltration pump to resume operation so that the dialyzer can continue to perform hemodialysis.

[0036] In this implementation, after calculating the blood chamber pressure drop at the current moment as the detection result, the ultrafiltration pump is restarted, which in turn pressurizes the dialysate in the dialysate circuit, pushing the dialysate to circulate in the dialysate circuit, thereby enabling the dialyzer to continue performing hemodialysis.

[0037] A second aspect of the present invention provides an HD single-pump machine, comprising a dialyzer, a dialysate circuit, a blood circuit, a detection module, and a main control module, wherein: the dialyzer is used for performing hemodialysis and includes a semipermeable membrane; the dialysate circuit flows through the outer side of the semipermeable membrane, and the inner side of the semipermeable membrane is a blood chamber, through which the blood circuit flows; the detection module and the main control module are electrically connected and are used to acquire the return pressure value, the blood chamber outlet pressure value, the dialysis flow rate, and the dialysate pressure difference coefficient of the dialysate circuit and send them to the main control module; the main control module is used to set the dialysate pressure value outside the semipermeable membrane equal to the blood chamber pressure value inside the semipermeable membrane, and then calculate the blood chamber pressure drop based on the return pressure value, the blood chamber outlet pressure value, the dialysis flow rate, and the dialysate pressure difference coefficient.

[0038] In this implementation, the side of the dialysate flowing into the dialyzer via the dialysate circuit is the supply end, and the side of the dialysate flowing out of the dialyzer via the dialysate circuit is the return end. A detection module is installed on the single pump unit. After acquiring the return end pressure value, blood chamber outlet pressure value, dialysis flow rate, and dialysate pressure difference coefficient of the dialysate circuit, the detection module transmits this data to the main control module via circuit transmission. The main control module has a processor capable of calculating the blood chamber pressure drop based on the return end pressure value, blood chamber outlet pressure value, dialysis flow rate, and dialysate pressure difference coefficient.

[0039] In one possible implementation, the main control module calculates the blood chamber pressure drop based on the return fluid pressure value, the blood chamber outlet pressure value, the dialysis flow rate, and the dialysate pressure difference coefficient, using a specific formula as shown in Equation 1:

[0040] PB = (PDo + PDo + K*F) d ) - 2PV (Equation 1)

[0041] Wherein, PB is the blood chamber pressure drop, PV is the blood chamber outlet pressure, PDo is the return fluid pressure, K is the dialysate pressure differential coefficient, and F... d The dialysis flow rate is [value missing].

[0042] In this implementation, the main control module stores the calculation formula shown in Equation 1. After receiving the data transmitted by the detection module through the circuit, the main control module has a processor that can automatically run the relevant calculation program to calculate the blood chamber pressure drop based on the return fluid pressure value, the blood chamber outlet pressure value, the dialysis flow rate and the dialysate pressure difference coefficient data.

[0043] In one possible implementation, the HD single-pump machine further includes an ultrafiltration pump located at the return end of the dialysate circuit; the main control module is used to make the dialysate pressure outside the semipermeable membrane equal to the blood chamber pressure inside the semipermeable membrane, including: the main control module is used to control the ultrafiltration pump to stop running, thereby making the dialysate pressure outside the semipermeable membrane equal to the blood chamber pressure inside the semipermeable membrane.

[0044] In this implementation, the ultrafiltration pump is used to regulate the pressure in the dialysate circuit, driving the dialysate to circulate within the circuit. The main control module is electrically connected to the ultrafiltration pump, thereby controlling the pump to operate normally or pause via electronic signals. When the main control module controls the ultrafiltration pump to pause, the dialysate pressure in the dialysate circuit is no longer affected by the additional pressure applied by the ultrafiltration pump, but only by the static pressure. At this time, based on the physical characteristics of the semipermeable membrane, the dialysate pressure outside the semipermeable membrane will gradually become consistent with the blood chamber pressure inside the semipermeable membrane, eventually achieving a dynamic pressure balance between the inside and outside of the semipermeable membrane, thus making the dialysate pressure outside the semipermeable membrane equal to the blood chamber pressure inside the semipermeable membrane.

[0045] In one possible implementation, after the main control module automatically runs a relevant calculation program to calculate the blood chamber pressure drop based on the return fluid pressure value, the blood chamber outlet pressure value, the dialysis flow rate, and the dialysate pressure difference coefficient, the main control module controls the ultrafiltration pump to resume operation via electronic signals so that the dialyzer can continue to perform hemodialysis.

[0046] In one possible implementation, the main control module further includes a touch screen, wherein: the main control module receives preset touch commands through the touch screen, thereby controlling the ultrafiltration pump and / or the detection module based on the touch commands; the touch screen is also used to display the return fluid pressure value, the blood chamber outlet pressure value, the dialysis flow rate, the dialysate pressure differential coefficient, and the blood chamber pressure drop.

[0047] In this implementation, an operation interface is displayed on the touchscreen, allowing users to interact with it through touch commands such as clicking and swiping. This enables the main control module to control the ultrafiltration pump to operate normally or pause based on these touch commands, or to control the detection module to detect the return pressure, blood chamber outlet pressure, dialysis flow rate, and dialysate pressure differential coefficient. This implementation allows users to more conveniently control the detection process of blood chamber pressure drop in the HD single-pump machine, increasing its ease of use and practicality. Furthermore, the touchscreen can display the return pressure, blood chamber outlet pressure, dialysis flow rate, dialysate pressure differential coefficient, and blood chamber pressure drop received by the main control module in real time, facilitating user monitoring of the HD single-pump machine's operation.

[0048] In one possible implementation, the main control module is also used to store data, wherein: when the main control module completes a detection of the blood chamber pressure drop, the main control module stores the time of the detection, and stores the return pressure value, the blood chamber outlet pressure value, the dialysis flow rate, the dialysate pressure difference coefficient, and the blood chamber pressure drop in that detection.

[0049] In this implementation, the main control module pauses the ultrafiltration pump, causing the dialysate pressure outside the semipermeable membrane to equal the blood chamber pressure inside the membrane. The blood chamber pressure drop is then calculated based on the return pressure, the blood chamber outlet pressure, the dialysis flow rate, and the dialysate pressure difference coefficient. Each cycle of restarting the ultrafiltration pump is considered a single detection of the blood chamber pressure drop. This implementation stores the time and data of each blood chamber pressure drop detection, allowing the main control module to record the historical operation of the HD single-pump machine. Users can view the stored data to understand the HD single-pump machine's operation at different times, enhancing its applicability.

[0050] In one possible implementation, the detection module includes a dialysate pressure sensor and a venous pressure sensor, wherein: the dialysate pressure sensor is located at the return end of the dialysate circuit and is electrically connected to the main control module, for acquiring the return end pressure value and sending the return end pressure value to the main control module; the venous pressure sensor is located at the outlet end of the blood chamber and is electrically connected to the main control module, for acquiring the blood chamber outlet pressure value and sending the blood chamber outlet pressure value to the main control module.

[0051] In this implementation, the side of the dialysate flowing into the dialyzer via the dialysate circuit is the supply end, and the side of the dialysate flowing out of the dialyzer via the dialysate circuit is the return end. The dialysate pressure sensor is installed at the return end of the dialysate circuit and detects the dialysate pressure value at the return end, thereby transmitting the return end pressure data to the main control module via circuitry. In the medical field, the pressure at the blood chamber inlet is also known as the pre-filter pressure, and the pressure at the blood chamber outlet is also known as the venous pressure. The venous pressure sensor is installed at the blood chamber outlet and detects the blood pressure value at the blood chamber outlet, thereby transmitting the blood chamber outlet pressure data to the main control module via circuitry. The installation positions of the dialysate pressure sensor and the venous pressure sensor are far from the blood pump at the blood chamber inlet of the dialyzer, so their detection accuracy will not be interfered with by the blood pump.

[0052] The method for detecting blood chamber pressure drop in an HD single-pump machine and the HD single-pump machine provided by the present invention have at least the following advantages compared with the prior art:

[0053] The aforementioned method for detecting blood chamber pressure drop in a single-pump dialyzer involves setting the dialysate pressure outside the semipermeable membrane to equal the blood chamber pressure inside the membrane during hemodialysis. Based on this condition, the invention acquires the return pressure, dialysis flow rate, and dialysate pressure difference coefficient of the dialysate circuit outside the membrane, and the outlet pressure of the blood chamber inside the membrane. By using the data from outside the membrane, the pressure drop of the blood chamber inside the membrane is indirectly obtained. This solves the technical problem of existing single-pump dialyzers being unable to detect blood chamber pressure drop, even when the single-pump dialyzer lacks a pressure sensor at the blood chamber inlet and cannot acquire the inlet pressure value. Furthermore, this invention can detect blood chamber pressure drop using only the existing equipment of the single-pump dialyzer, eliminating the need for an additional pressure sensor at the blood chamber inlet.

[0054] Existing HD single-pump dialyzers are irreplaceable for their applicable medical procedures. Adding an additional pressure sensor to an existing HD single-pump dialyzer is not only difficult to implement and yields unsatisfactory results, but may also disrupt the original streamlined structure of the existing HD single-pump dialyzer, leading to adverse technical effects. Therefore, this invention utilizes only the existing equipment of the HD single-pump dialyzer to detect blood chamber pressure drop, eliminating the need for an additional pressure sensor at the dialyzer blood chamber inlet. This makes it easy to promote and use in the field, demonstrating outstanding practicality. Attached Figure Description

[0055] Figure 1 This is a flowchart of a method for detecting blood chamber pressure drop in an HD single-pump machine provided by an embodiment of the present invention;

[0056] Figure 2 This is a schematic diagram of the pressure change of blood as it flows from the dialyzer blood chamber to the dialyzer blood chamber, provided in an embodiment of the present invention.

[0057] Figure 3 This is a schematic diagram of the pressure change of the dialysate from flowing into the dialyzer to flowing out of the dialyzer, provided in an embodiment of the present invention.

[0058] Figure 4 This is a structural diagram of an HD single-pump machine provided in an embodiment of the present invention;

[0059] Figure 5 This is a schematic diagram of the circuit structure of an HD single pump provided in an embodiment of the present invention;

[0060] The components include: 1. Dialysis fluid circuit; 11. Supply valve; 12. Return valve; 13. Ultrafiltration pump; 14. Balance chamber; 2. Blood circuit; 21. Venous chamber; 22. Blood pump; 23. Arterial chamber; 3. Dialyzer; 4. Main control module; 41. Touch screen; 5. Detection module; 51. Dialysis fluid pressure sensor; 52. Venous pressure sensor. Detailed Implementation

[0061] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0062] The following detailed descriptions are exemplary and intended to provide further detailed explanation of the invention. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein in the specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings are used to distinguish different objects and not to describe a particular order.

[0063] It should be understood that although the steps in the flowcharts of the accompanying drawings are shown in sequence as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some of the steps in the flowcharts of the accompanying drawings may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.

[0064] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0065] See Figure 1 This invention provides a method for detecting blood chamber pressure drop in a single-pump HD dialyzer. The HD dialyzer includes a dialyzer, a dialysate circuit, and a blood circuit. The dialyzer includes a semi-permeable membrane. The dialysate circuit flows through the outer side of the semi-permeable membrane, and the inner side of the semi-permeable membrane is the blood chamber. The blood circuit flows through the blood chamber. The method includes the following steps:

[0066] S101. When the dialyzer is performing hemodialysis, the dialysate pressure on the outside of the semipermeable membrane is made equal to the blood chamber pressure on the inside of the semipermeable membrane.

[0067] S102. Obtain the return pressure value, blood chamber outlet pressure value, dialysis flow rate, and dialysate pressure difference coefficient of the dialysate circuit.

[0068] S103. The blood chamber pressure drop is calculated based on the return fluid pressure value, the blood chamber outlet pressure value, the dialysis flow rate, and the dialysate pressure difference coefficient, and the blood chamber pressure drop is used as the detection result.

[0069] In one possible implementation, the specific calculation formula for the blood chamber pressure drop based on the return fluid pressure value, the blood chamber outlet pressure value, the dialysis flow rate, and the dialysate pressure difference coefficient is as follows: Formula 1:

[0070] PB = (PDo + PDo + K*F) d ) - 2PV (Equation 1)

[0071] Wherein, PB is the blood chamber pressure drop, PV is the blood chamber outlet pressure, PDo is the return fluid pressure, K is the dialysate pressure differential coefficient, and F... d The dialysis flow rate is [value missing].

[0072] It should be noted that the pressure drop in the blood chamber specifically refers to the pressure at the inlet of the blood chamber minus the pressure at the outlet of the blood chamber. In the medical field, the pressure at the inlet of the blood chamber is also known as the pre-filter pressure, and the pressure at the outlet of the blood chamber is also known as the venous pressure. Therefore, the pressure drop in the dialyzer blood chamber can also be described as equal to the pre-filter pressure minus the venous pressure, which can be expressed by the following formula 2:

[0073] PB = PA - PV (Equation 2)

[0074] Wherein, PB is the pressure drop of the blood chamber, PV is the pressure value at the outlet of the blood chamber, and PA is the pressure value at the inlet of the blood chamber.

[0075] See Figure 2 For the blood circuit flowing through the blood chamber, due to resistance during blood flow, the pressure of blood flowing out of the dialyzer blood chamber is lower than the pressure flowing into the dialyzer blood chamber; that is, the pressure at the blood chamber outlet is lower than the pressure at the blood chamber inlet, and this pressure decrease is linear. Therefore, the blood chamber pressure inside the dialyzer semipermeable membrane is equal to the average of the blood chamber inlet pressure and the blood chamber outlet pressure, which can be expressed as Equation 3:

[0076] Pb = (PA + PV) / 2 (Equation 3)

[0077] Wherein, Pb is the blood chamber pressure value, PA is the blood chamber inlet pressure value, and PV is the blood chamber outlet pressure value.

[0078] It should also be noted that in the medical field, the end of the dialysate circuit in a HD single-pump machine that flows into the dialyzer has a supply valve, which can be called the supply end, and the end of the dialysate circuit that flows out of the dialyzer has a return valve, which can be called the return end. The pressure values ​​at the supply end and the return end have the mathematical relationship shown in Equation 4 below:

[0079] Pn = PDi - PDo = K*F d (Equation 4)

[0080] Wherein, Pn is the pressure difference between the dialysate flowing into and out of the dialyzer, i.e., the pressure difference between the supply end and the return end; PDi is the pressure value at the supply end; PDo is the pressure value at the return end; K is the dialysate pressure difference coefficient; and F... d The dialysis flow rate is [value missing].

[0081] See Figure 3 For the dialysate circuit flowing outside the semipermeable membrane, since there is also resistance during the flow of dialysate in the circuit, the pressure of the dialysate flowing out of the dialyzer will be less than the pressure flowing into the dialyzer. That is, the pressure at the return end of the dialysate circuit is less than the pressure at the supply end of the dialysate circuit, and this pressure decrease is a linear decrease. Therefore, the dialysate pressure outside the semipermeable membrane of the dialyzer is equal to the average of the supply end pressure and the return end pressure, which can be expressed as Equation 5:

[0082] Pd = (PDi + PDo) / 2 (Formula 5)

[0083] Wherein, Pd is the dialysate pressure outside the semipermeable membrane, PDi is the supply pressure, and PDo is the return pressure.

[0084] In this implementation, by setting the dialysate pressure Pd outside the semipermeable membrane to be equal to the blood chamber pressure Pb inside the semipermeable membrane, the physical quantities in the HD single-pump machine at this moment have the physical relationship described in Equation 6:

[0085] Pb = ( PA + PV ) / 2 = Pd = ( PDi + PDo ) / 2 (Equation 6)

[0086] Wherein, Pb is the blood chamber pressure value, PA is the blood chamber inlet pressure value, PV is the blood chamber outlet pressure value, Pd is the dialysate pressure value outside the semipermeable membrane, PDi is the supply pressure value, and PDo is the return pressure value. Based on this, by combining the physical relationships of Equations 6, 4, and 2, the physical calculation formula shown in Equation 1 can be obtained. Through the above technical means, this implementation method can detect the blood chamber pressure drop at the current moment without obtaining the blood chamber inlet pressure value, solving the technical problem that existing HD single-pump machines cannot detect the blood chamber pressure drop, and eliminating the need to install an additional pressure sensor at the dialyzer blood chamber inlet, making it easy to promote and use in this field.

[0087] See Figure 4 and Figure 5 This invention provides an HD single-pump machine, including a dialysate circuit 1, a supply valve 11, a return valve 12, a balance chamber 14, a blood circuit 2, a venous chamber 21, a blood pump 22, an arterial chamber 23, a dialyzer 3, a main control module 4, and a detection module 5.

[0088] Wherein: the dialyzer 3 is used for hemodialysis, and includes a semipermeable membrane. The dialysate circuit 1 flows through the outer side of the semipermeable membrane, and the inner side of the semipermeable membrane is a blood chamber. The blood circuit 2 flows through the blood chamber. The supply valve 11 is located at the supply end of the dialysate circuit 1, and the supply valve 11 is electrically connected to the main control module 4, used to control the opening or closing of the supply end of the dialysate circuit 1. The return valve 12 is located at the return end of the dialysate circuit 1, and the return valve 12 is electrically connected to the main control module 4, used to control the opening or closing of the return end of the dialysate circuit 1. The balance chamber 14 is electrically connected to the main control module 4, used to control the dialysis flow rate of the dialysate circuit 1. The venous reservoir 21 is used to capture residual microbubbles in the blood and prevent bubble backflow. The blood pump 22 is electrically connected to the main control module and is used to regulate the pressure in the blood circuit, propelling the blood to circulate within it. The arterial chamber 23 reduces arterial blood eddies and turbulence, ensuring a stable flow rate as blood enters the dialyzer. The detection module 5 is electrically connected to the main control module 4 and is used to acquire the return pressure, blood chamber outlet pressure, dialysis flow rate, and dialysate pressure differential coefficient of the dialysate circuit and send these values ​​to the main control module 4. The main control module 4 controls the opening and closing of the supply valve 11 and the return valve 12. When the main control module 4 controls the supply valve 11 and the return valve 12 to open, the dialysate in the dialysate circuit 1 can flow through the dialyzer 3, thus circulating within the circuit. The main control module 4 also controls the balance chamber 15, thereby controlling the dialysis flow rate in the dialysate circuit 1. The main control module 4 is also used to control the normal operation of the blood pump 22, thereby regulating the pressure in the blood circuit and promoting the circulation of blood in the blood circuit. The main control module 4 is used to make the dialysate pressure outside the semipermeable membrane equal to the blood chamber pressure inside the semipermeable membrane, and then calculate the blood chamber pressure drop based on the return pressure, the blood chamber outlet pressure, the dialysis flow rate, and the dialysate pressure difference coefficient.

[0089] In this embodiment, the side where the dialysate flows into the dialyzer 3 via the dialysate circuit 1 is the supply end, and the side where the dialysate flows out of the dialyzer 3 via the dialysate circuit 1 is the return end. The detection module 5 is installed on the single pump unit. After acquiring the return end pressure value, blood chamber outlet pressure value, dialysis flow rate, and dialysate pressure difference coefficient of the dialysate circuit 1, the detection module 5 transmits the above data to the main control module 4 via circuit transmission. The main control module 4 has a processor and can calculate the blood chamber pressure drop based on the return end pressure value, the blood chamber outlet pressure value, the dialysis flow rate, and the dialysate pressure difference coefficient.

[0090] In one possible embodiment, the main control module 4 calculates the blood chamber pressure drop using the specific formula shown in Equation 1, based on the return fluid pressure value, the blood chamber outlet pressure value, the dialysis flow rate, and the dialysate pressure difference coefficient.

[0091] PB = (PDo + PDo + K*F) d ) - 2PV (Equation 1)

[0092] Wherein, PB is the blood chamber pressure drop, PV is the blood chamber outlet pressure, PDo is the return fluid pressure, K is the dialysate pressure differential coefficient, and F... d The dialysis flow rate is [value missing].

[0093] In this implementation, the main control module 4 stores the calculation formula shown in Equation 1. After receiving the return fluid pressure value, the blood chamber outlet pressure value, the dialysis flow rate and the dialysate pressure difference coefficient data transmitted by the detection module 5 through the circuit, the main control module 4 automatically runs the relevant calculation program through its processor to calculate the blood chamber pressure drop.

[0094] See Figure 4 and Figure 5 In one possible embodiment, the HD single-pump machine further includes an ultrafiltration pump 13, which is located at the return end of the dialysate circuit 1; the main control module 4 is used to make the dialysate pressure outside the semipermeable membrane equal to the blood chamber pressure inside the semipermeable membrane, including: the main control module is used to control the ultrafiltration pump 13 to stop running, thereby making the dialysate pressure outside the semipermeable membrane equal to the blood chamber pressure inside the semipermeable membrane.

[0095] In this embodiment, the ultrafiltration pump 13 is used to regulate the pressure in the dialysate circuit 1, driving the dialysate to circulate in the circuit. The main control module 4 is electrically connected to the ultrafiltration pump 13, thereby controlling the ultrafiltration pump 13 to operate normally or stop operating via electronic signals. When the main control module 4 controls the ultrafiltration pump 13 to stop operating, the dialysate pressure in the dialysate circuit 1 is no longer affected by the additional pressure applied by the ultrafiltration pump 13, but only by the static pressure. At this time, based on the physical characteristics of the semipermeable membrane, the dialysate pressure outside the semipermeable membrane will gradually become consistent with the blood chamber pressure inside the semipermeable membrane, eventually achieving a dynamic pressure balance between the inside and outside of the semipermeable membrane, thus making the dialysate pressure outside the semipermeable membrane equal to the blood chamber pressure inside the semipermeable membrane.

[0096] In one possible embodiment, after the main control module 4 automatically runs a relevant calculation program to calculate the blood chamber pressure drop based on the return fluid pressure value, the blood chamber outlet pressure value, the dialysis flow rate, and the dialysate pressure difference coefficient data, the main control module 4 controls the ultrafiltration pump 13 to resume operation via electronic signals so that the dialyzer can continue to perform hemodialysis.

[0097] See Figure 4 and Figure 5 In one possible embodiment, the main control module further includes a touch screen 41, wherein: the main control module 4 receives preset touch commands through the touch screen 41, thereby controlling the ultrafiltration pump 13 and / or the detection module 5 based on the touch commands; the touch screen 41 is also used to display the return fluid pressure value, the blood chamber outlet pressure value, the dialysis flow rate, the dialysate pressure differential coefficient, and the blood chamber pressure drop.

[0098] In this embodiment, the touchscreen 41 displays an operation interface, allowing the user to interact with the touchscreen through touch commands such as clicking and swiping. This enables the main control module 4 to control the ultrafiltration pump 13 to operate normally or pause based on the touch commands, or to control the detection module 5 to detect the return pressure, the blood chamber outlet pressure, the dialysis flow rate, and the dialysate pressure differential coefficient. This implementation allows users to more conveniently control the detection process of the blood chamber pressure drop in the HD single-pump machine, increasing its ease of use and practicality. Furthermore, the touchscreen 41 can also display in real time the return pressure, blood chamber outlet pressure, dialysis flow rate, dialysate pressure differential coefficient, and blood chamber pressure drop received by the main control module 4, facilitating user monitoring of the HD single-pump machine's operation.

[0099] In one possible embodiment, the main control module 4 is also used to store data, wherein: when the main control module 4 completes a detection of the blood chamber pressure drop, the main control module 4 stores the time of the detection, and stores the return pressure value, the blood chamber outlet pressure value, the dialysis flow rate, the dialysate pressure difference coefficient and the blood chamber pressure drop in the detection.

[0100] In this embodiment, the main control module 4 controls the ultrafiltration pump 13 to pause operation, thereby making the dialysate pressure outside the semipermeable membrane equal to the blood chamber pressure inside the semipermeable membrane. The blood chamber pressure drop is then calculated based on the return pressure, the blood chamber outlet pressure, the dialysis flow rate, and the dialysate pressure difference coefficient. Finally, the process of controlling the ultrafiltration pump 13 to resume operation is considered one detection of the blood chamber pressure drop. This implementation stores the time and related data of each blood chamber pressure drop detection, allowing the main control module 4 to record the historical operation of the HD single-pump machine. Users can view the stored data to understand the operation of the HD single-pump machine at different times, enhancing the applicability of the HD single-pump machine.

[0101] See Figure 4 and Figure 5 In one possible embodiment, the detection module 5 includes a dialysate pressure sensor 51 and a venous pressure sensor 52, wherein: the dialysate pressure sensor 51 is located at the return end of the dialysate circuit 1 and is electrically connected to the main control module 4, for acquiring the return end pressure value and sending the return end pressure value to the main control module 4; the venous pressure sensor 52 is located at the outlet end of the blood chamber and is electrically connected to the main control module 4, for acquiring the blood chamber outlet pressure value and sending the blood chamber outlet pressure value to the main control module 4.

[0102] In this embodiment, the side where dialysate flows into dialyzer 3 via dialysate circuit 1 is the supply end, and the side where dialysate flows out of dialyzer 3 via dialysate circuit 1 is the return end. The dialysate pressure sensor 51 is installed at the return end of dialysate circuit 1 and detects the dialysate pressure value at the return end, thereby transmitting the return end pressure data to the main control module 4 via circuitry. In the medical field, the pressure at the blood chamber inlet is also known as the pre-filter pressure, and the pressure at the blood chamber outlet is also known as the venous pressure. The venous pressure sensor 52 is installed at the blood chamber outlet and detects the blood pressure value at the blood chamber outlet, thereby transmitting the blood chamber outlet pressure data to the main control module 4 via circuitry. The installation positions of the dialysate pressure sensor 51 and the venous pressure sensor 52 are far from the blood pump at the blood chamber inlet of dialyzer 3, so their detection accuracy will not be interfered with by the blood pump.

[0103] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0104] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0105] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various improvements and substitutions without departing from the concept of this application, and these improvements and substitutions should also be considered within the scope of protection of this invention. Therefore, the scope of protection of this application should be determined by the appended claims.

Claims

1. An HD single-pump unit, characterized in that, It includes a dialyzer, dialysate circuit, blood circuit, detection module, and main control module, among which: The dialyzer is used for performing hemodialysis and includes a semipermeable membrane. The dialysate circuit flows through the outer side of the semipermeable membrane, and the inner side of the semipermeable membrane is a blood chamber through which the blood circuit flows. The detection module and the main control module are electrically connected and are used to acquire the return pressure value, blood chamber outlet pressure value, dialysis flow rate and dialysis pressure difference coefficient of the dialysate circuit and send them to the main control module. The main control module is used to make the dialysate pressure outside the semipermeable membrane equal to the blood chamber pressure inside the semipermeable membrane, and then calculate the blood chamber pressure drop based on the return pressure, the blood chamber outlet pressure, the dialysis flow rate and the dialysate pressure difference coefficient.

2. The HD single pump machine according to claim 1, characterized in that, The main control module calculates the blood chamber pressure drop using the following formula based on the return fluid pressure value, the blood chamber outlet pressure value, the dialysis flow rate, and the dialysate pressure difference coefficient: PB = (PDo + PDo + K*F d ) - 2PV; Wherein, PB is the blood chamber pressure drop, PV is the blood chamber outlet pressure, PDo is the return fluid pressure, K is the dialysate pressure differential coefficient, and F... d The dialysis flow rate is [value missing].

3. The HD single pump machine according to claim 1, characterized in that, It also includes an ultrafiltration pump located at the return end of the dialysate circuit; the main control module is used to ensure that the dialysate pressure outside the semipermeable membrane is equal to the blood chamber pressure inside the semipermeable membrane, including: The main control module is used to control the ultrafiltration pump to stop running, thereby making the dialysate pressure outside the semipermeable membrane equal to the blood chamber pressure inside the semipermeable membrane.

4. The HD single pump machine according to claim 3, characterized in that, The main control module also includes a touch screen, wherein: The main control module receives preset touch commands through the touch screen, and then controls the ultrafiltration pump and / or the detection module based on the touch commands; The touch screen is also used to display the pressure value at the return end, the pressure value at the blood chamber outlet, the dialysis flow rate, the dialysate pressure differential coefficient, and the blood chamber pressure drop.

5. The HD single pump machine according to claim 1, characterized in that, The main control module is also used to store data, wherein: When the main control module completes a detection of the blood chamber pressure drop, the main control module stores the time of the detection, and stores the return pressure value, the blood chamber outlet pressure value, the dialysis flow rate, the dialysate pressure difference coefficient, and the blood chamber pressure drop in that detection.

6. The HD single pump machine according to claim 1, characterized in that, The detection module includes a dialysate pressure sensor and a venous pressure sensor, wherein: The dialysate pressure sensor is located at the return end of the dialysate circuit and is electrically connected to the main control module. It is used to acquire the pressure value at the return end and send the pressure value at the return end to the main control module. The venous pressure sensor is located at the outlet end of the blood chamber and is electrically connected to the main control module. It is used to acquire the pressure value at the outlet end of the blood chamber and send the pressure value at the outlet end of the blood chamber to the main control module.

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