A method and device for continuous monitoring of recirculation rate in VV ECMO

Abstract

This application relates to a method, apparatus, computer equipment, and storage medium for continuous monitoring of VV ECMO recirculation rate. The method includes: acquiring the patient's pulmonary carbon dioxide output, membrane lung carbon dioxide output, membrane lung inlet oxygen saturation, membrane lung outlet oxygen saturation, and cardiac output; calculating the total carbon dioxide output and dividing it by the respiratory quotient to obtain oxygen consumption; calculating venous oxygen content using arterial oxygen content, oxygen consumption, and cardiac output based on the Fick principle, and then calculating central venous oxygen saturation based on the venous oxygen content; calculating the VV ECMO recirculation rate based on the membrane lung inlet oxygen saturation, membrane lung outlet oxygen saturation, and central venous oxygen saturation; and repeating the above steps at preset time intervals. This application achieves continuous real-time monitoring of the VV ECMO recirculation rate without requiring additional specialized equipment or frequent blood sampling.

Description

Technical Field

[0001] This application relates to the field of extracorporeal life support equipment technology, and in particular to a method, apparatus, computer equipment, and storage medium for continuous monitoring of VV ECMO recirculation rate. Background Technology

[0002] VV ECMO (Venovenous Extracorporeal Membrane Oxygenation) is a crucial life support method for patients with severe respiratory failure. During VV ECMO operation, oxygenated blood is returned to the patient's venous system via a return tube, subsequently entering the right heart, pulmonary circulation, and systemic circulation. However, when the drainage tube and return tube are positioned close together, some of the returned blood is re-absorbed into the ECMO circuit before entering the systemic circulation, resulting in recirculation. Recirculation leads to a decrease in effective oxygen supply and reduced flow utilization by ECMO, which are key indicators that need to be monitored in the clinical management of VV ECMO.

[0003] Currently, commonly used clinical methods for measuring recirculation include ultrasonic dilution, thermodilution, and blood oxygen saturation calculation. Ultrasonic dilution involves injecting normal saline into the tubing and using an ultrasonic sensor to detect the dilution curve to quantify recirculation; thermodilution involves injecting cold saline into the tubing and calculating recirculation based on temperature changes; and blood oxygen saturation calculation requires collecting venous blood from the patient for blood gas analysis.

[0004] However, the above methods generally have the following problems: ultrasonic dilution and thermal dilution require additional specialized monitoring equipment and require the injection of liquid into the tubing; blood oxygen saturation calculation method requires frequent blood sampling; and none of these methods can achieve continuous real-time monitoring of recirculation rate. Summary of the Invention

[0005] Therefore, it is necessary to provide a method, apparatus, computer equipment, and storage medium for continuous real-time monitoring of VV ECMO recirculation rate without the need for additional specialized equipment and frequent blood sampling, in order to address the aforementioned technical problems.

[0006] Firstly, this application provides a method for continuous monitoring of the recirculation rate of VV ECMO. The method includes: S1: Obtain the patient's lung carbon dioxide output, membrane lung carbon dioxide output, membrane lung inlet oxygen saturation, membrane lung outlet oxygen saturation, and cardiac output. S2: Add the patient's pulmonary carbon dioxide output to the membrane lung carbon dioxide output to obtain the patient's total carbon dioxide output; divide the patient's total carbon dioxide output by the respiratory quotient to obtain the patient's oxygen consumption; calculate the patient's arterial oxygen content based on the patient's hemoglobin concentration and arterial oxygen saturation; calculate the patient's venous oxygen content based on the Fick principle using the patient's arterial oxygen content, the patient's oxygen consumption, and the patient's cardiac output; calculate the patient's central venous oxygen saturation based on the patient's venous oxygen content. S3: According to the formula Calculate the VV ECMO recirculation rate, where, This indicates the oxygen saturation at the inlet of the membrane lung. This indicates the oxygen saturation at the membrane lung outlet. This indicates the patient's central venous oxygen saturation. S4: Repeat S1 to S3 at preset time intervals to obtain the VV ECMO recirculation rate at each time point.

[0007] In one embodiment, the patient's arterial oxygen content is determined according to a formula. Calculate, where, This indicates the patient's hemoglobin concentration. Indicates the patient's arterial blood oxygen saturation. This indicates the patient's arterial oxygen partial pressure.

[0008] In one embodiment, the patient's venous oxygen content is determined according to the formula... Calculate, where, This indicates the patient's oxygen consumption. This indicates the patient's cardiac output.

[0009] In one embodiment, the patient's central venous oxygen saturation is determined according to the formula... Calculate, where, This indicates the patient's venous oxygen partial pressure.

[0010] In one embodiment, the patient's cardiac output is obtained by continuous non-invasive monitoring using chest impedance.

[0011] In one embodiment, the patient's carbon dioxide output is calculated according to the formula... Calculate, where, Indicates the patient's exhaled gas flow rate. This indicates the concentration of carbon dioxide in the patient's exhaled breath.

[0012] In one embodiment, the carbon dioxide output of the membrane lung is calculated according to the formula... Calculate, where, Indicates scavenging air flow rate, This indicates the partial pressure of carbon dioxide at the scavenging gas outlet. This indicates the partial pressure of carbon dioxide at the scavenging gas inlet. Indicates atmospheric pressure. This represents the temperature and pressure correction factor.

[0013] Secondly, this application also provides a device for continuous monitoring of VV ECMO recirculation rate. The device includes: The parameter acquisition module is used to acquire the patient's lung carbon dioxide output, membrane lung carbon dioxide output, membrane lung inlet blood oxygen saturation, membrane lung outlet blood oxygen saturation, and the patient's cardiac output. The oxygen metabolism parameter calculation module is used to add the patient's pulmonary carbon dioxide output to the membrane lung carbon dioxide output to obtain the patient's total carbon dioxide output; divide the patient's total carbon dioxide output by the respiratory quotient to obtain the patient's oxygen consumption; calculate the patient's arterial oxygen content based on the patient's hemoglobin concentration and arterial oxygen saturation; calculate the patient's venous oxygen content based on the Fick principle using the patient's arterial oxygen content, the patient's oxygen consumption, and the patient's cardiac output; and calculate the patient's central venous oxygen saturation based on the patient's venous oxygen content. The recirculation rate calculation module is used to calculate the recirculation rate according to the formula. Calculate the VV ECMO recirculation rate, where, This indicates the oxygen saturation at the inlet of the membrane lung. This indicates the oxygen saturation at the membrane lung outlet. This indicates the patient's central venous oxygen saturation. The timed triggering module is used to trigger the parameter acquisition module, the oxygen metabolism parameter calculation module, and the recirculation rate calculation module at preset time intervals to obtain the VV ECMO recirculation rate at each time point.

[0014] Thirdly, this application also provides a computer device. The computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the above-described method for continuous monitoring of VV ECMO recirculation rate.

[0015] Fourthly, this application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program thereon, which, when executed by a processor, implements the above-described method for continuous monitoring of VV ECMO recirculation rate.

[0016] The aforementioned method, device, computer equipment, and storage medium for continuous monitoring of VV ECMO recirculation rate acquires the patient's pulmonary carbon dioxide output, membrane lung carbon dioxide output, membrane lung inlet oxygen saturation, membrane lung outlet oxygen saturation, and cardiac output. It then uses the respiratory quotient and Fick principle to invert the patient's venous oxygen saturation and calculate the VV ECMO recirculation rate. This achieves the technical effect of continuous real-time monitoring of the recirculation rate without the need for ultrasonic dilution equipment, injection of fluid into the tubing, or frequent blood sampling. It improves the ability to assess the efficiency of VV ECMO operation and provides a quantitative basis for catheter position adjustment. Attached Figure Description

[0017] Figure 1 This is a diagram illustrating the application environment of a continuous monitoring method for VV ECMO recirculation rate in one embodiment. Figure 2 This is a flowchart illustrating a method for continuous monitoring of VV ECMO recirculation rate in one embodiment. Figure 3 This is a structural block diagram of a continuous monitoring device for VV ECMO recirculation rate in one embodiment; Figure 4 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0019] The continuous monitoring method for VV ECMO recirculation rate provided in this application embodiment can be applied to VV ECMO devices or patient monitoring devices / workstations used in conjunction with such devices. The method acquires patient physiological parameters through sensors and monitoring modules built into the VV ECMO device, and the processor of the VV ECMO device performs continuous calculation and output of the recirculation rate, thereby achieving continuous real-time monitoring of the VV ECMO recirculation rate.

[0020] The collection and processing of patient physiological parameters involved in the embodiments of this application are necessary for clinical diagnosis and treatment, and the data processing activities are conducted within the scope necessary for clinical diagnosis and treatment. Data processors shall, in accordance with the law, inform patients of the necessity of processing sensitive personal information and its impact on their personal rights, and obtain the patients' informed consent; at the same time, data processors shall take necessary management and technical measures to ensure data security and prevent data leakage or illegal use. When implementing this application, clinical institutions shall, in accordance with the requirements of relevant laws, regulations, and medical ethics, legally protect patients' right to know, right to privacy, and right to personal information.

[0021] Firstly, in the clinical management of VV ECMO, accurate monitoring of the recirculation rate is crucial for assessing ECMO operational efficiency and guiding clinical intervention. However, existing methods for measuring the recirculation rate rely on ultrasonic dilution equipment or require frequent blood sampling for blood gas analysis, making continuous monitoring impossible. Therefore, in one embodiment, such as... Figure 2 As shown, a method for continuous monitoring of VVECMO recirculation rate is provided, which can be applied to... Figure 1 Taking the VV ECMO device as an example, the following steps are included: S1: Obtain the patient's lung carbon dioxide output, membrane lung carbon dioxide output, membrane lung inlet oxygen saturation, membrane lung outlet oxygen saturation, and cardiac output. S2: Add the patient's pulmonary carbon dioxide output to the membrane lung carbon dioxide output to obtain the patient's total carbon dioxide output; divide the patient's total carbon dioxide output by the respiratory quotient to obtain the patient's oxygen consumption; calculate the patient's arterial oxygen content based on the patient's hemoglobin concentration and arterial oxygen saturation; calculate the patient's venous oxygen content based on the patient's arterial oxygen content, patient oxygen consumption, and patient cardiac output according to Fick's principle; calculate the patient's central venous oxygen saturation based on the patient's venous oxygen content. S3: According to the formula: Calculate the VV ECMO recirculation rate, where, Indicates the oxygen saturation at the membrane lung inlet. Indicates the oxygen saturation at the membrane lung outlet. This indicates the patient's central venous oxygen saturation. S4: Repeat S1 to S3 at preset time intervals to obtain the VV ECMO recirculation rate at each time point.

[0022] In step S1, the patient's pulmonary carbon dioxide output represents the amount of carbon dioxide expelled from the lungs through spontaneous breathing or mechanical ventilation, measured in mL / min. The membrane lung carbon dioxide output represents the amount of carbon dioxide expelled by the membrane lung (oxygenator) in the VV ECMO circuit through scavenging gas, measured in mL / min. The membrane lung inlet oxygen saturation represents the oxygen saturation of the blood before entering the membrane lung, expressed as a percentage. The membrane lung outlet oxygen saturation represents the oxygen saturation of the blood after leaving the membrane lung and before being reinfused into the patient, expressed as a percentage. The patient's cardiac output represents the amount of blood pumped by the patient's heart per minute, measured in L / min.

[0023] The aforementioned parameters can be obtained through the sensors and monitoring modules configured in the VV ECMO device itself, or through patient monitoring equipment or monitoring workstations used in conjunction with the VV ECMO device. For example, the patient's lung carbon dioxide output can be measured by a ventilator or metabolic monitor; the membrane lung carbon dioxide output can be obtained by monitoring the carbon dioxide concentration on the membrane lung's sweeping side; the membrane lung inlet and outlet oxygen saturation can be obtained by oxygen saturation sensors installed in the pre- and post-membrane tubing; and the patient's cardiac output can be obtained through methods such as chest impedance, ultrasound, or thermodilution. All the aforementioned sensors and monitoring modules can be connected to the execution entity using any of the existing technologies to achieve data transmission; this embodiment does not limit this.

[0024] In step S2, the patient's total carbon dioxide output is equal to the patient's lung carbon dioxide output. With membrane lung carbon dioxide output The sum of This indicates the rate at which the patient expels total carbon dioxide. Respiratory Quotient (RQ) This represents the ratio between the patient's carbon dioxide output and oxygen consumption, and can be taken as 0.8. Dividing the patient's total carbon dioxide output by the respiratory quotient yields the patient's oxygen consumption. ,Right now .

[0025] According to Fick's Principle (a fundamental physiological principle based on the law of conservation of mass, proposed by Adolf Fick; its core idea is that under steady-state conditions, the rate at which an organ (or the whole body) takes up or releases a substance (such as oxygen) is equal to the blood flow through that organ multiplied by the concentration difference of that substance in arterial and venous blood), it can be concluded that a patient's oxygen consumption is equal to cardiac output multiplied by the difference in oxygen content between arteries and veins. ,in Indicates the patient's cardiac output. Indicates the patient's arterial oxygen content, This represents the patient's venous oxygen content. After transforming this equation, the patient's venous oxygen content can be calculated using the patient's arterial oxygen content, oxygen consumption, and cardiac output: The unit conversions involved in this calculation (such as the conversion between oxygen content (mL / dL) and oxygen consumption (mL / min), and cardiac output (L / min)) are handled by those skilled in the art according to the specific unit system used and the Fick principle. After obtaining the patient's venous oxygen content, the patient's central venous oxygen saturation can be obtained based on the conversion relationship between oxygen content and blood oxygen saturation.

[0026] In step S3, the membrane lung inlet oxygen saturation reflects the actual oxygen saturation of the blood drawn into the ECMO circuit through the drainage tube. This blood includes a portion of the reinfused blood that has been oxygenated by the membrane lung and a portion of venous blood from the patient's systemic circulation. The membrane lung outlet oxygen saturation reflects the oxygen saturation of the blood after adequate oxygenation by the membrane lung. The patient's central venous oxygen saturation reflects the patient's true central venous oxygen saturation. The recirculation rate, calculated using the above formula, represents the percentage of blood flow re-drawn into the ECMO circuit through the drainage tube relative to the total ECMO flow. A higher recirculation rate indicates more severe recirculation and a lower effective oxygen supply from the ECMO.

[0027] In step S4, the preset time interval can be set according to clinical monitoring needs, for example, it can be set to repeat once every 1 minute, every 5 minutes, or every 10 minutes. Each complete execution of steps S1 to S3 yields the VV ECMO recirculation rate at the current time point. By continuously repeating the above steps at preset time intervals, the VV ECMO recirculation rate at multiple time points can be obtained.

[0028] Through the above steps S1 to S4, the VV ECMO device can acquire all the necessary physiological parameters using its own sensors and monitoring modules. It uses the respiratory quotient to convert the patient's total carbon dioxide output into oxygen consumption, and then uses the Fick principle to invert the patient's venous oxygen content and central venous blood oxygen saturation. Finally, it substitutes these parameters into the recirculation rate definition formula to calculate the recirculation rate. The above calculation process is repeated at preset time intervals, thereby achieving continuous real-time monitoring of the VV ECMO recirculation rate without the need for ultrasonic dilution equipment, injection of fluid into the tubing, or frequent blood sampling.

[0029] In actual clinical calculations, it is necessary to clarify the specific formula for calculating arterial oxygen content. Therefore, in one embodiment, the patient's arterial oxygen content is calculated according to the following formula: in, This indicates the patient's hemoglobin concentration. Indicates the patient's arterial blood oxygen saturation. This indicates the patient's arterial oxygen partial pressure.

[0030] Specifically, the patient's hemoglobin concentration is measured in g / dL and can be obtained through routine blood tests. The patient's arterial oxygen saturation is a percentage value and can be obtained through pulse oximetry or arterial blood gas analysis. The patient's arterial oxygen partial pressure is measured in mmHg and can be obtained through arterial blood gas analysis.

[0031] The oxygen content in blood consists of two parts: the first part is oxygen bound to hemoglobin, with each gram of hemoglobin binding approximately 1.34 mL of oxygen. Therefore, the amount of oxygen bound to hemoglobin equals 1.34 multiplied by the hemoglobin concentration and then by the blood oxygen saturation. The second part is oxygen dissolved in plasma. At each mmHg oxygen partial pressure, the amount of dissolved oxygen in blood is 0.003 mL per dL. Therefore, the amount of dissolved oxygen equals 0.003 multiplied by the arterial oxygen partial pressure. The sum of these two parts is the arterial oxygen content, expressed in mL / dL.

[0032] The above formula provides a clear mathematical expression for calculating arterial oxygen content, enabling accurate calculation of the patient's arterial oxygen content and providing accurate input parameters for subsequent calculation of venous oxygen content based on the Fick principle.

[0033] When calculating a patient's venous oxygen content based on the Fick principle, it is necessary to clarify the specific formula for calculating venous oxygen content. Therefore, in one embodiment, the patient's venous oxygen content is calculated according to the following formula: in, This indicates the patient's oxygen consumption. This indicates the patient's cardiac output.

[0034] Specifically, the unit for patient oxygen consumption is mL / min. The unit for patient cardiac output is L / min.

[0035] According to Fick's principle, a patient's oxygen consumption equals cardiac output multiplied by the arteriovenous oxygen difference. ,Right now After transforming the equation, we can obtain... The "×10" in the formula is a unit conversion factor: oxygen content. and The unit is mL / dL, oxygen consumption The unit for cardiac output is mL / min, while the unit for cardiac output is L / min. 1 L equals 10 dL, therefore it is necessary to... Then multiply by 10 to keep the dimensions of the equation consistent.

[0036] The above formula provides a clear mathematical expression for calculating venous oxygen content. Given the patient's arterial oxygen content, oxygen consumption, and cardiac output, the patient's venous oxygen content can be accurately calculated without the need to collect venous blood for blood gas analysis.

[0037] When calculating central venous oxygen saturation based on a patient's venous oxygen content, a specific calculation formula needs to be defined. Therefore, in one embodiment, the patient's central venous oxygen saturation is calculated according to the formula... Calculate, where, This indicates the patient's venous oxygen partial pressure.

[0038] Specifically, The unit is mL / dL. The unit is mmHg, which can be obtained through central venous blood gas analysis or through continuous monitoring by a sensor placed in a central venous system. The unit is g / dL.

[0039] Venous oxygen content represents the total amount of oxygen contained in a unit volume of venous blood, including oxygen bound to hemoglobin and oxygen dissolved in plasma. The amount of oxygen dissolved in plasma is equal to 0.003 multiplied by the partial pressure of oxygen in the vein, expressed in mL / dL. Subtracting the dissolved oxygen portion from the venous oxygen content yields the amount of oxygen bound to hemoglobin. Dividing this by the oxygen capacity of hemoglobin (each gram of hemoglobin can bind 1.34 mL of oxygen multiplied by the hemoglobin concentration) gives the patient's central venous oxygen saturation as a percentage.

[0040] The above formula provides a clear mathematical expression for calculating central venous oxygen saturation. Given the patient's venous oxygen content, venous oxygen partial pressure, and hemoglobin concentration, the patient's central venous oxygen saturation can be accurately calculated.

[0041] When acquiring a patient's cardiac output, it is necessary to specify the exact acquisition method to ensure the real-time nature and continuity of the cardiac output data. Therefore, in one embodiment, the patient's cardiac output is obtained through continuous non-invasive monitoring using chest impedance method.

[0042] Specifically, the thoracic impedance method is a non-invasive cardiac output monitoring method based on bioimpedance technology. Its basic principle is to measure cardiac output by utilizing changes in thoracic cavity impedance during each cardiac cycle. With the contraction and relaxation of the heart, the blood flow velocity, blood volume, and volume within the aorta undergo periodic changes, resulting in periodic impedance changes on the surface of the thoracic cavity. By placing electrodes on the surface of the thoracic cavity, applying a weak high-frequency alternating current, and measuring the corresponding voltage changes, the thoracic cavity impedance signal can be obtained. Based on the measured changes in thoracic cavity impedance, the stroke volume can be calculated, and multiplying it by the heart rate yields the cardiac output. The thoracic impedance monitoring device can be connected to the execution unit using any existing connection method to transmit cardiac output data; this embodiment does not limit this.

[0043] The above method enables patients to continuously and in real time acquire cardiac output in a non-invasive manner, without the need to insert catheters or inject fluids into the patient's body, and without causing additional trauma or infection risk to the patient, providing real-time and accurate cardiac output input parameters for continuous monitoring of recirculation rate.

[0044] When obtaining a patient's lung carbon dioxide output, it is necessary to specify the exact method of acquisition or calculation to ensure the accuracy and availability of this parameter. Therefore, in one embodiment, the patient's lung carbon dioxide output is calculated according to the formula... Calculate, where, Indicates the patient's exhaled gas flow rate. This indicates the concentration of carbon dioxide in the patient's exhaled breath.

[0045] Specifically, the patient's exhaled gas flow rate is measured in L / min and can be obtained using the gas flow sensor on the ventilator or metabolic monitor. The fractional concentration of carbon dioxide in the patient's exhaled gas is a dimensionless percentage value and can be measured using the carbon dioxide concentration sensor on the ventilator or metabolic monitor.

[0046] The total amount of carbon dioxide expelled by a patient through the lungs is equal to the total volume of exhaled gas per unit time multiplied by the volume fraction of carbon dioxide in the exhaled gas. Multiplying the exhaled gas flow rate by the carbon dioxide concentration in the exhaled gas yields the patient's carbon dioxide expulsion rate, expressed in L / min. The aforementioned gas flow sensor and carbon dioxide concentration sensor can be connected to the actuator using any existing connection method to achieve data transmission; this embodiment does not limit this.

[0047] The above formula provides a clear mathematical expression for calculating the patient's pulmonary carbon dioxide output, enabling accurate calculation of this output using parameters obtained from conventional respiratory monitoring equipment. This provides accurate input parameters for subsequent calculations of the patient's total carbon dioxide output. In practical applications, pulmonary carbon dioxide output can also be directly measured using metabolic monitoring equipment; this embodiment does not limit this approach.

[0048] When obtaining the carbon dioxide output of a membrane lung, it is necessary to specify the exact method of acquisition or calculation to ensure the accuracy and availability of this parameter. Therefore, in one embodiment, the carbon dioxide output of the membrane lung is calculated according to the formula... Calculate, where, Indicates scavenging air flow rate, This indicates the partial pressure of carbon dioxide at the scavenging gas outlet. This indicates the partial pressure of carbon dioxide at the scavenging gas inlet. Indicates atmospheric pressure. This represents the temperature and pressure correction factor.

[0049] Specifically, the flow rate of the scavenging gas flowing through the membrane lung is measured in L / min and can be obtained by a gas flow meter installed in the membrane lung scavenging circuit. The partial pressure of carbon dioxide in the gas at the membrane lung scavenging outlet is measured in mmHg and can be obtained by a carbon dioxide partial pressure sensor installed in the scavenging outlet pipeline. The partial pressure of carbon dioxide in the gas at the membrane lung scavenging inlet is also measured in mmHg. The scavenging inlet is typically filled with fresh gas, and its carbon dioxide partial pressure is usually close to 0 mmHg; this can also be obtained by a carbon dioxide partial pressure sensor installed in the scavenging inlet pipeline. The ambient atmospheric pressure is measured in mmHg and can be obtained by a barometer or by taking an approximation of 760 mmHg under standard atmospheric pressure. The temperature and pressure correction factor is used to correct the gas volume to standard conditions; this factor can be calculated from the actual measured temperature and ambient pressure according to the ideal gas law.

[0050] The membrane lung removes carbon dioxide from the blood and expels it through scavenging gas. As the scavenging gas flows through the membrane lung, carbon dioxide in the blood diffuses through the hollow fiber membrane to the scavenging gas side. The increase in carbon dioxide partial pressure in the scavenging gas is obtained by subtracting the partial pressure at the scavenging inlet from the partial pressure at the scavenging outlet. Dividing this pressure difference by atmospheric pressure yields the volume fraction increase of carbon dioxide in the scavenging gas, which is then multiplied by the scavenging flow rate to obtain the volume of carbon dioxide expelled by the membrane lung per unit time. Finally, multiplying by a temperature and pressure correction factor corrects the gas volume to standard conditions, yielding the standardized carbon dioxide expulsion rate of the membrane lung, expressed in L / min. The gas flow meter and carbon dioxide partial pressure sensor described above can be connected to the actuator using any existing connection method to achieve data transmission; this embodiment does not limit this.

[0051] The above formula provides a clear mathematical expression for calculating the carbon dioxide output of the membrane lung, enabling accurate calculation of the carbon dioxide output using parameters obtained from routine monitoring in the membrane lung sweeping circuit, thus providing accurate input parameters for subsequent calculation of the patient's total carbon dioxide output.

[0052] The following is a detailed procedure for continuously monitoring the recirculation rate of a VV ECMO patient.

[0053] The first step is to obtain the patient's physiological parameters. The following parameters are obtained through the sensors and monitoring modules configured in the VV ECMO device: carbon dioxide output from the patient's lungs. The carbon dioxide excretion rate of the membrane lung is 120 mL / min. The oxygen saturation at the membrane lung inlet was 80 mL / min. The oxygen saturation at the membrane lung outlet was 82%. The patient's cardiac output is 100%. The flow rate was 5.0 L / min. The patient's hemoglobin concentration was obtained through blood gas analysis. The patient's arterial oxygen saturation was 10 g / dL. The accuracy rate is 95%. All of the above parameters can be obtained through the sensors and monitoring modules configured in the VV ECMO device itself, or through patient monitoring equipment or monitoring workstations used with the VV ECMO device.

[0054] The second step is to calculate the patient's total carbon dioxide output. The amount of carbon dioxide expelled from the patient's lungs. With membrane lung carbon dioxide output Adding them together, we get the patient's total carbon dioxide excretion: mL / min The third step is to calculate the patient's oxygen consumption. Respiratory Quotient The value is 0.8, representing the patient's total carbon dioxide excretion. Divided by respiratory quotient The patient's oxygen consumption was obtained: mL / min The fourth step is to calculate the patient's arterial oxygen content. Based on the patient's hemoglobin concentration 10g / dL, arterial blood oxygen saturation It is 95%, calculated according to the oxygen content formula: Among them, dissolved oxygen item Since the value is small, the effect of dissolved oxygen is ignored in this embodiment. Therefore: mL / dL The fifth step is to calculate the patient's venous oxygen content based on the Fick principle. Fick's principle states that, under steady-state conditions, the total oxygen consumption of the whole body... Equal to cardiac output Arterial-venous oxygen content difference The product of, i.e. By combining the units of each parameter and transforming the equation, we can obtain: Substitute the values: mL / dL Step 6: Calculate the patient's central venous oxygen saturation. Based on the conversion relationship between venous oxygen content and blood oxygen saturation: Among them, dissolved oxygen item Since the value is small, the effect of dissolved oxygen is ignored in this embodiment. Therefore: Central venous oxygen saturation of the patient Approximately 57.7%.

[0055] Step 7: Calculate the VV ECMO recirculation rate According to the formula for calculating the recycling rate: Substitute the values: Step 8: Issue an early warning message. According to the ELSO guidelines for VV ECMO management, clinical intervention is required when the recirculation rate exceeds 30%. In this embodiment, the calculated recirculation rate is approximately 57.4%, exceeding the preset threshold of 30%. Therefore, the system issues an alarm message to remind clinicians to investigate.

[0056] Through the above steps, this embodiment realizes the continuous calculation of the recirculation rate based on the physiological parameters that the VV ECMO device itself can obtain, without the need for ultrasonic dilution equipment, injection of liquid into the tubing, or frequent blood sampling, and issues a timely warning when the recirculation rate exceeds a preset threshold, providing a quantitative basis for clinical intervention.

[0057] It should be understood that although the steps in the flowcharts of the above embodiments are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated 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 steps in the flowcharts of the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps.

[0058] Secondly, based on the same inventive concept, this application also provides an apparatus for implementing the continuous monitoring method for VV ECMO recirculation rate described above. The solution provided by this apparatus is similar to the solution described in the above method; therefore, specific limitations in one or more apparatus embodiments provided below can be found in the limitations of the continuous monitoring method for VV ECMO recirculation rate described above, and will not be repeated here.

[0059] In one embodiment, such as Figure 3 As shown, the device includes: a parameter acquisition module, an oxygen metabolism parameter calculation module, a recirculation rate calculation module, and a timed triggering module. Among them: The parameter acquisition module is used to acquire the patient's lung carbon dioxide output, membrane lung carbon dioxide output, membrane lung inlet blood oxygen saturation, membrane lung outlet blood oxygen saturation, and the patient's cardiac output. The oxygen metabolism parameter calculation module is used to add the patient's pulmonary carbon dioxide output to the membrane lung carbon dioxide output to obtain the patient's total carbon dioxide output; divide the patient's total carbon dioxide output by the respiratory quotient to obtain the patient's oxygen consumption; calculate the patient's arterial oxygen content based on the patient's hemoglobin concentration and arterial oxygen saturation; calculate the patient's venous oxygen content based on the Fick principle using the patient's arterial oxygen content, patient oxygen consumption, and patient cardiac output; and calculate the patient's central venous oxygen saturation based on the patient's venous oxygen content. The recirculation rate calculation module is used to calculate the recirculation rate according to the formula. Calculate the VV ECMO recirculation rate, where, Indicates the oxygen saturation at the inlet of the membrane lung. Indicates the oxygen saturation at the membrane lung outlet. This indicates the patient's central venous oxygen saturation. The timed trigger module is used to trigger the parameter acquisition module, oxygen metabolism parameter calculation module, and recirculation rate calculation module at preset time intervals to obtain the VV ECMO recirculation rate at each time point.

[0060] In one embodiment, the oxygen metabolism parameter calculation module includes a patient arterial oxygen content calculation unit. This unit calculates the patient's arterial oxygen content using the following formula: in, This indicates the patient's hemoglobin concentration. Indicates the patient's arterial blood oxygen saturation. This indicates the patient's arterial oxygen partial pressure.

[0061] In one embodiment, the oxygen metabolism parameter calculation module includes a patient venous oxygen content calculation unit. This patient venous oxygen content calculation unit calculates the patient's venous oxygen content using the following formula: in, This indicates the patient's oxygen consumption. This indicates the patient's cardiac output.

[0062] In one embodiment, the oxygen metabolism parameter calculation module includes a venous oxygen saturation calculation unit. This venous oxygen saturation calculation unit calculates the patient's central venous oxygen saturation using the following formula: in, This indicates the patient's venous oxygen partial pressure.

[0063] In one embodiment, the parameter acquisition module includes a patient cardiac output acquisition unit. This patient cardiac output acquisition unit is used to obtain the patient's cardiac output through continuous non-invasive monitoring using chest impedance method.

[0064] In one embodiment, the parameter acquisition module includes a lung carbon dioxide output acquisition unit. The lung carbon dioxide output acquisition unit is used to calculate the lung carbon dioxide output using the following formula: in, Indicates the patient's exhaled gas flow rate. This indicates the concentration of carbon dioxide in the patient's exhaled breath.

[0065] In one embodiment, the parameter acquisition module includes a membrane lung carbon dioxide emission acquisition unit. This membrane lung carbon dioxide emission acquisition unit is used to calculate the membrane lung carbon dioxide emission using the following formula: in, Indicates scavenging air flow rate, This indicates the partial pressure of carbon dioxide at the scavenging gas outlet. This indicates the partial pressure of carbon dioxide at the scavenging gas inlet. Indicates atmospheric pressure. This represents the temperature and pressure correction factor.

[0066] Each module in the aforementioned continuous monitoring device for VV ECMO recirculation rate can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0067] In one embodiment, a computer device is provided, which may be a VV ECMO device, or a patient monitoring device or monitoring workstation used in conjunction with a VV ECMO device. Its internal structure diagram may be as follows: Figure 4As shown. The computer device includes a processor, memory, and communication interface connected via a system bus. The processor provides computational and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The communication interface is used to communicate with external sensors or monitoring modules via wired or wireless means to obtain patient physiological parameters. When the computer program is executed by the processor, it implements the steps of the continuous monitoring method for VV ECMO recirculation rate described in the above embodiments. When the computer device is a VV ECMO device, it also includes ECMO circuit components such as a membrane lung, blood pump, tubing, and oxygenator. When the computer device is a supporting patient monitoring device or monitoring workstation, it interacts with the VV ECMO device via the communication interface.

[0068] Those skilled in the art will understand that Figure 4 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0069] Thirdly, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of any of the methods described in the above method embodiments.

[0070] Fourthly, a computer-readable storage medium is provided, on which a computer program is stored, which, when executed by a processor, implements the steps of any of the methods described in the above method embodiments.

[0071] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing a processor in a VV ECMO device or its associated monitoring device. The computer program can be stored in a non-volatile computer-readable storage medium. When executed by the processor, the computer program implements the process of the continuous monitoring method for VV ECMO recirculation rate as described in the above method embodiments. The processor can be integrated into the VV ECMO device or located in a patient monitoring device or monitoring workstation used in conjunction with the VV ECMO device. Any references to memory, database, or other media used in the embodiments provided in this application may include at least one of non-volatile and volatile memory. Non-volatile memory may 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 may include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The databases involved in the various embodiments provided in this application may include at least one of relational databases and non-relational databases. Non-relational databases may include blockchain-based distributed databases, etc., and are not limited thereto. The processors involved in the various 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. It should be noted that the collection and processing of patient physiological parameters involved in the above process are all carried out within the scope necessary for clinical diagnosis and treatment, and comply with the requirements of relevant laws, regulations and medical ethics, so as to legally protect the patient's right to know and personal information rights.

[0072] 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.

[0073] 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 patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for continuous monitoring of VV ECMO recirculation rate, characterized in that, The method includes: S1: Obtain the patient's lung carbon dioxide output, membrane lung carbon dioxide output, membrane lung inlet oxygen saturation, membrane lung outlet oxygen saturation, and cardiac output. S2: Add the patient's pulmonary carbon dioxide output to the membrane lung carbon dioxide output to obtain the patient's total carbon dioxide output; divide the patient's total carbon dioxide output by the respiratory quotient to obtain the patient's oxygen consumption; calculate the patient's arterial oxygen content based on the patient's hemoglobin concentration and arterial oxygen saturation; calculate the patient's venous oxygen content based on the Fick principle using the patient's arterial oxygen content, the patient's oxygen consumption, and the patient's cardiac output; calculate the patient's central venous oxygen saturation based on the patient's venous oxygen content. S3: According to the formula Calculate the VV ECMO recirculation rate, where, This indicates the oxygen saturation at the inlet of the membrane lung. This indicates the oxygen saturation at the membrane lung outlet. This indicates the patient's central venous oxygen saturation. S4: Repeat S1 to S3 at preset time intervals to obtain the VV ECMO recirculation rate at each time point.

2. The method according to claim 1, characterized in that, The patient's arterial oxygen content is based on the formula. Calculate, where, This indicates the patient's hemoglobin concentration. Indicates the patient's arterial blood oxygen saturation. This indicates the patient's arterial oxygen partial pressure.

3. The method according to claim 2, characterized in that, The patient's venous oxygen content is based on the formula. Calculate, where, Indicates the patient's oxygen consumption. This indicates the patient's cardiac output.

4. The method according to claim 3, characterized in that, The patient's central venous oxygen saturation is calculated according to the formula. Calculate, where, This indicates the patient's venous oxygen partial pressure.

5. The method according to claim 1, characterized in that, The patient's cardiac output was obtained through continuous non-invasive monitoring using the chest impedance method.

6. The method according to claim 1, characterized in that, The patient's lung carbon dioxide output is calculated according to the formula. Calculate, where, Indicates the patient's exhaled gas flow rate. This indicates the concentration of carbon dioxide in the patient's exhaled breath.

7. The method according to claim 1, characterized in that, The carbon dioxide excretion of the membrane lung is based on the formula. Calculate, where, Indicates scavenging air flow rate, This indicates the partial pressure of carbon dioxide at the scavenging gas outlet. This indicates the partial pressure of carbon dioxide at the scavenging gas inlet. Indicates atmospheric pressure. This represents the temperature and pressure correction factor.

8. A continuous monitoring device for VV ECMO recirculation rate, characterized in that, The device includes: The parameter acquisition module is used to acquire the patient's lung carbon dioxide output, membrane lung carbon dioxide output, membrane lung inlet blood oxygen saturation, membrane lung outlet blood oxygen saturation, and the patient's cardiac output. The oxygen metabolism parameter calculation module is used to add the patient's pulmonary carbon dioxide output to the membrane lung carbon dioxide output to obtain the patient's total carbon dioxide output; divide the patient's total carbon dioxide output by the respiratory quotient to obtain the patient's oxygen consumption; calculate the patient's arterial oxygen content based on the patient's hemoglobin concentration and arterial oxygen saturation; calculate the patient's venous oxygen content based on the Fick principle using the patient's arterial oxygen content, the patient's oxygen consumption, and the patient's cardiac output; and calculate the patient's central venous oxygen saturation based on the patient's venous oxygen content. The recirculation rate calculation module is used to calculate the recirculation rate according to the formula. Calculate the VV ECMO recirculation rate, where, This indicates the oxygen saturation at the inlet of the membrane lung. This indicates the oxygen saturation at the membrane lung outlet. This indicates the patient's central venous oxygen saturation. The timed triggering module is used to trigger the parameter acquisition module, the oxygen metabolism parameter calculation module, and the recirculation rate calculation module at preset time intervals to obtain the VV ECMO recirculation rate at each time point.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the method for continuous monitoring of VV ECMO recirculation rate as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the method for continuous monitoring of the VV ECMO recirculation rate as described in any one of claims 1 to 7.

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