Crnt fluid management decision system and method based on hemodynamic monitoring

Abstract

This invention relates to the field of blood purification control technology, and discloses a CRRT fluid management decision-making system and method based on hemodynamic monitoring, comprising: a blood flow acquisition module for acquiring systolic blood pressure, mean arterial pressure, and heart rate to form a current hemodynamic dataset and determine a baseline dataset; a grading determination module for determining the hemodynamic grade based on the current hemodynamic dataset and the baseline dataset; a dehydration boundary module for determining the hard boundary of the net dehydration rate; a dehydration command module for generating and trimming net dehydration commands; a pump control linkage module for writing net dehydration commands and linkage adjustment of replacement fluid flow rate and dialysate flow rate; a safety control module for entering or de-entering a safety mode and updating the net dehydration command; and a termination and takeover module for outputting a stop control command or a manual takeover flag. This invention achieves automatic decision-making and orderly execution of net dehydration operations under safe conditions during continuous blood purification.

Description

Technical Field

[0001] This invention belongs to the field of blood purification control technology, specifically relating to a CRRT fluid management decision system and method based on hemodynamic monitoring. Background Technology

[0002] Continuous renal replacement therapy (CRRT) is a commonly used blood purification method for critically ill patients, widely applied in clinical settings such as acute kidney injury, sepsis, and multiple organ dysfunction. During CRRT treatment, fluid management, especially the net dehydration process, has a significant impact on maintaining circulatory stability. Excessively rapid or improperly controlled net dehydration rates can easily lead to hemodynamic complications such as hypotension and insufficient tissue perfusion, while insufficient dehydration can result in fluid retention, affecting treatment efficacy.

[0003] Existing CRRT devices typically offer net dehydration control based on prescription parameters, relying heavily on healthcare professionals setting fixed net dehydration rates based on experience or adjusting them manually. While some devices can collect monitoring parameters such as blood pressure and heart rate, these parameters are mostly used for display or alarms, failing to form a continuous, closed-loop linkage decision-making mechanism with net dehydration control. Especially in cases of rapidly changing conditions in critically ill patients, relying solely on absolute thresholds or human experience is insufficient to reflect changes in the patient's hemodynamic status in a timely and accurate manner, posing certain safety risks.

[0004] Furthermore, existing technologies lack a systematic approach to the relationship between net dehydration control and solute clearance dosage. When net dehydration adjustments affect clearance dosage distribution, manual readjustment of replacement fluid or dialysate flow rates is often required, increasing operational complexity and compromising treatment stability. Summary of the Invention

[0005] This invention provides a CRRT fluid management decision system and method based on hemodynamic monitoring, which solves the technical problems in related technologies, such as net dehydration control mainly relying on fixed prescription parameters or human experience, lack of continuous linkage between hemodynamic monitoring results and net dehydration adjustment, and difficulty in timely and safe constraints on net dehydration rate and fluid distribution when hemodynamic state changes.

[0006] This invention provides a CRRT fluid management decision system based on hemodynamic monitoring, comprising: The blood flow acquisition module is used to acquire systolic blood pressure, mean arterial pressure, and heart rate to form the current hemodynamic dataset, and to determine the baseline dataset based on a stable acquisition cycle; The grading module is used to calculate the relative change rate of mean arterial pressure and the heart rate-systolic pressure ratio based on the current hemodynamic dataset and the baseline dataset, and match them with a preset fixed threshold table to obtain the hemodynamic grade. The dehydration boundary module is used to determine the hard boundary of the net dehydration rate based on hemodynamic grade and patient weight; The dehydration instruction module is used to read the target cumulative net dehydration amount and the completed cumulative net dehydration amount to determine the net dehydration instruction, and to hard-cut the net dehydration instruction according to the net dehydration rate. The pump control linkage module is used to write the net dehydration command into the net ultrafiltration control channel of the CRRT equipment, keep the total removal dose constant, and determine the replacement fluid flow rate and dialysate flow rate according to the total removal dose and the net dehydration command when the net dehydration and total removal dose are not completely decoupled. The safety control module is used to enter the safety mode when the hemodynamic level meets the preset conditions, set the net dehydration command to zero and execute the fluid replacement volume in the safety mode, lock the observation period number in the continuous safety mode, and release the safety mode and update the net dehydration command after the recovery trigger period number threshold is met. The termination takeover module is used to output a stop control command and set the net dehydration command to zero when the cumulative net dehydration amount reaches the target cumulative net dehydration amount. When in safe mode and the safe mode is not released within the number of safe mode lock observation periods, it outputs a manual takeover flag.

[0007] This invention provides a CRRT fluid management decision-making method based on hemodynamic monitoring, comprising the following steps: Step 71: Collect systolic blood pressure, mean arterial pressure, and heart rate to form the current hemodynamic dataset, and determine the baseline dataset based on the stable acquisition cycle; Step 72: Calculate the relative change rate of mean arterial pressure and the heart rate-systolic pressure ratio based on the current hemodynamic dataset and the baseline dataset, and match them with a preset fixed threshold table to obtain the hemodynamic level; Step 73: Determine the hard boundary of net dehydration rate based on hemodynamic grade and patient weight; Step 74: Read the target cumulative net dehydration amount and the completed cumulative net dehydration amount to determine the net dehydration command, and cut the net dehydration command according to the hard boundary of the net dehydration rate; Step 75: Write the net dehydration command into the net ultrafiltration control channel of the CRRT device, keep the total removal dose constant, and determine the replacement fluid flow rate and dialysate flow rate based on the total removal dose and the net dehydration command when the net dehydration and total removal dose are not completely decoupled. Step 76: When the hemodynamic level meets the preset conditions, enter the safety mode, set the net dehydration command to zero and execute the safety mode fluid resuscitation volume, lock the observation period number in the continuous safety mode, and release the safety mode and update the net dehydration command after the recovery trigger period number threshold is met. Step 77: When the cumulative net dehydration amount reaches the target cumulative net dehydration amount, output a stop control command and set the net dehydration command to zero. When in safe mode and the safe mode is not released within the number of safe mode lock observation periods, output a manual takeover flag.

[0008] The beneficial effects of this invention are as follows: This invention systematically integrates hemodynamic monitoring information with the fluid management and control process of CRRT equipment, forming a continuous and executable decision-making and control mechanism. By constructing a current hemodynamic dataset and a baseline dataset, and classifying the hemodynamic state based on relative changes, net dehydration control no longer relies on a single absolute threshold or human experience, but can be dynamically assessed in conjunction with the patient's individual stable reference state.

[0009] This invention introduces a hard boundary for the net dehydration rate based on patient weight and hemodynamic grade, explicitly constraining the net dehydration command and ensuring that the fluid removal process is always limited within a safe range that matches the patient's current physiological state. Simultaneously, in a device control mode where net dehydration and total clearance dose are not completely decoupled, the replacement fluid flow rate and dialysate flow rate are linked for adjustment, ensuring that the predetermined clearance treatment intensity is maintained while adjusting the fluid management strategy.

[0010] Furthermore, this invention incorporates a safety mode and a termination / intervention mechanism. It automatically limits net dehydration procedures when hemodynamic conditions deteriorate or persist abnormally, and prompts for manual intervention when necessary, thus establishing a clear boundary between automatic control and manual intervention. Overall, this invention improves the safety, controllability, and consistency of CRRT fluid management. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the modules of the CRRT fluid management decision system based on hemodynamic monitoring of the present invention. Detailed Implementation

[0012] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the subject matter described herein, and changes may be made to the function and arrangement of the elements discussed without departing from the scope of this specification. Various processes or components may be omitted, substituted, or added as needed in the examples. Furthermore, features described in some examples may be combined in other examples.

[0013] like Figure 1 As shown, the CRRT fluid management decision system based on hemodynamic monitoring includes: Blood flow acquisition module 1 is used to acquire systolic blood pressure, mean arterial pressure, and heart rate to form the current hemodynamic dataset, and to determine the baseline dataset based on a stable acquisition cycle; The grading module 2 is used to calculate the relative change rate of mean arterial pressure and the heart rate-systolic pressure ratio based on the current hemodynamic dataset and the baseline dataset, and match them with a preset fixed threshold table to obtain the hemodynamic grade. Dehydration boundary module 3 is used to determine the hard boundary of net dehydration rate based on hemodynamic grade and patient weight; The dehydration instruction module 4 is used to read the target cumulative net dehydration amount and the completed cumulative net dehydration amount to determine the net dehydration instruction, and to cut the net dehydration instruction according to the hard boundary of the net dehydration rate. Pump control linkage module 5 is used to write the net dehydration command into the net ultrafiltration control channel of the CRRT equipment, keep the total removal dose constant, and determine the replacement fluid flow rate and dialysate flow rate according to the total removal dose and the net dehydration command when the net dehydration and total removal dose are not completely decoupled. Safety control module 6 is used to enter safety mode when the hemodynamic level meets the preset conditions, set the net dehydration command to zero and execute the fluid replacement volume in safety mode, lock the observation period number in continuous safety mode, and release safety mode and update net dehydration command after the threshold of the recovery trigger period number is met. The termination control module 7 is used to output a stop control command and set the net dehydration command to zero when the completed cumulative net dehydration reaches the target cumulative net dehydration. When in safe mode and the safe mode is not released within the number of safe mode lock observation periods, it outputs a manual takeover flag.

[0014] In one embodiment of the present invention, systolic blood pressure, mean arterial pressure, and heart rate are collected to form a current hemodynamic dataset, and a baseline dataset is determined based on a stable acquisition cycle, including: Step 11: Synchronously collect the patient's systolic blood pressure, mean arterial pressure, and heart rate according to a preset collection cycle. The preset collection cycle is a fixed time interval used to limit the sampling frequency of hemodynamic parameters to ensure the temporal continuity and comparability of the data. Each collection generates a collection record, which includes at least the corresponding systolic blood pressure, mean arterial pressure, heart rate, and collection timestamp. The system writes each collection record into the storage structure in ascending order of the collection timestamp, thereby forming the current hemodynamic dataset. In this way, the hemodynamic changes of the patient during CRRT treatment can be fully reflected.

[0015] Step 12: After forming the current hemodynamic dataset, to avoid short-term fluctuations or abnormal interference affecting subsequent fluid management decisions, the system further extracts continuous acquisition records as candidate windows from the current hemodynamic dataset based on a baseline acquisition cycle number threshold. The baseline acquisition cycle number threshold is used to limit the number of acquisition records included in the candidate window, thereby ensuring that the candidate window corresponds to a representative time interval. For each candidate window, the system calculates the systolic blood pressure fluctuation value, mean arterial pressure fluctuation value, and heart rate fluctuation value. Specifically, the systolic blood pressure fluctuation value is the difference between the maximum and minimum systolic blood pressure values ​​within the candidate window; the mean arterial pressure fluctuation value is the difference between the maximum and minimum mean arterial pressure values ​​within the candidate window; and the heart rate fluctuation value is the difference between the maximum and minimum heart rate values ​​within the candidate window. These fluctuation values ​​are used to quantitatively characterize the stability of hemodynamic parameters within the time interval.

[0016] The fluctuation values ​​of systolic blood pressure, mean arterial pressure, and heart rate are compared with their corresponding stability thresholds. These stability thresholds are pre-set thresholds used to limit parameter fluctuations within physiologically acceptable ranges. When all three fluctuation values ​​within a candidate window do not exceed their respective stability thresholds, the system determines that the candidate window as a stable acquisition period. This determination method allows for the selection of relatively stable hemodynamic time segments from the current hemodynamic dataset, thereby avoiding the introduction of drastic fluctuations or unstable states into the baseline reference.

[0017] Step 13: After determining a stable acquisition period, the system further calculates baseline representative values ​​for the acquisition records within that stable acquisition period. Specifically, the systolic blood pressure values ​​obtained from each acquisition within the stable acquisition period are summed and divided by the number of acquisition values ​​to obtain a representative systolic blood pressure value; the mean arterial pressure values ​​obtained from each acquisition within the stable acquisition period are summed and divided by the number of acquisition values ​​to obtain a representative mean arterial pressure value; and the heart rate values ​​obtained from each acquisition within the stable acquisition period are summed and divided by the number of acquisition values ​​to obtain a representative heart rate value. These representative values ​​are used to characterize the typical hemodynamic level of the patient in a stable state. Finally, the system writes the representative systolic blood pressure value, representative mean arterial pressure value, representative heart rate value, and stable acquisition period identifier into a baseline dataset.

[0018] Through the above implementation methods, this invention constructs a hemodynamic baseline dataset based on real monitoring data during CRRT treatment. This baseline dataset is derived from hemodynamically stable periods and can serve as an important reference basis for subsequent hemodynamic grade determination, net dehydration rate boundary determination, and fluid management decisions. This allows the CRRT fluid management decision-making process to be based on reliable physiological benchmarks, improving the safety and stability of continuous blood purification treatment.

[0019] In one embodiment of the present invention, the relative rate of change of mean arterial pressure and the heart rate-systolic pressure ratio are calculated based on the current hemodynamic dataset and the baseline dataset, and the hemodynamic level is obtained by matching them with a preset fixed threshold table, including: Step 21: Select the acquisition record corresponding to the latest acquisition timestamp from the current hemodynamic dataset as the acquisition record for this cycle. The acquisition record for this cycle represents the latest hemodynamic monitoring result acquired within the current control cycle. The system extracts the current systolic blood pressure, current mean arterial pressure, and current heart rate from the acquisition record for this cycle, and simultaneously reads the baseline mean arterial pressure from the baseline dataset. The baseline mean arterial pressure is a representative value of mean arterial pressure calculated within a stable acquisition cycle, used to characterize the patient's reference hemodynamic level under relatively stable conditions.

[0020] Step 22 involves quantifying the degree of hemodynamic change. Specifically, the difference between the baseline mean arterial pressure (MAP) and the current MAP is used as the numerator, and the baseline MAP is used as the denominator. The ratio of the numerator to the denominator is calculated to obtain the relative rate of change of MAP. This relative rate of change reflects the degree of deviation of the current MAP from the baseline level. Simultaneously, the ratio of the current heart rate as the numerator and the current systolic blood pressure as the denominator is calculated to obtain the heart rate-systolic blood pressure ratio. This ratio comprehensively reflects the relationship between heart rate changes and systolic blood pressure levels, characterizing a certain degree of hemodynamic load.

[0021] Step 23: Compare the relative change rate of mean arterial pressure with the threshold intervals of the relative change rate of mean arterial pressure in the preset fixed threshold table one by one, and compare the heart rate-systolic pressure ratio with the threshold intervals of the heart rate-systolic pressure ratio in the preset fixed threshold table one by one. When the relative change rate of mean arterial pressure and the heart rate-systolic pressure ratio both fall into the threshold interval corresponding to the same entry, output the hemodynamic level corresponding to that entry. The preset fixed threshold table is a pre-set reference table, in which each entry contains a set of threshold intervals of the relative change rate of mean arterial pressure and a set of threshold intervals of the heart rate-systolic pressure ratio, and corresponds one-to-one with a hemodynamic level.

[0022] Hemodynamic grades include: stable, mildly restricted, restricted, and dangerous. This classification maps the patient's current hemodynamic status from quantitative indicators to a clear grading result, providing a direct basis for determining net dehydration rate boundaries, triggering safe modes, and making CRRT fluid management decisions.

[0023] Through the above implementation methods, the present invention quantitatively assesses and grades the hemodynamic status based on the relative change relationship between the current hemodynamic data and the stable baseline data, avoiding the influence of individual differences caused by relying solely on a single absolute value judgment, and enabling CRRT fluid management decisions to be more in line with the patient's current physiological state.

[0024] In one embodiment of the present invention, in order to safely constrain the net dehydration process during CRRT treatment and prevent excessively rapid or large fluid removal from adversely affecting the patient's hemodynamic stability, the system includes a dehydration boundary module to determine the hard boundary of the net dehydration rate. This hard boundary of the net dehydration rate serves as an important constraint for the subsequent generation and pruning of net dehydration commands, limiting the range of net dehydration rates that the CRRT device is allowed to execute per unit time.

[0025] Specifically, the dehydration boundary module first acquires the patient's weight. This patient weight is a body mass parameter input and stored before or during treatment, reflecting the patient's baseline fluid volume. The system multiplies the patient's weight by a fixed coefficient to determine the upper limit of the baseline net dehydration rate. This fixed coefficient is a pre-set proportionality coefficient used to convert the patient's weight into the corresponding upper limit of the baseline net dehydration rate; its value is used to limit the range of the maximum acceptable net dehydration rate per unit body weight. By introducing the patient's weight parameter, the upper limit of the baseline net dehydration rate can be adaptively adjusted according to individual patient differences, avoiding the risk of over-dehydration caused by using a fixed absolute value.

[0026] After determining the upper limit of the baseline net dehydration rate, the system further dynamically adjusts the upper limit of the net dehydration rate based on the patient's current hemodynamic status. Specifically, based on the hemodynamic level determined in the preceding steps, the system retrieves the fixed reduction factor corresponding to the current hemodynamic level from a correspondence table between hemodynamic levels and fixed reduction factors. This correspondence table is a pre-defined mapping table used to reflect the different levels of safety constraints on the net dehydration rate under different hemodynamic levels. The more restricted the hemodynamic status, the smaller the corresponding fixed reduction factor, thus lowering the allowable upper limit of the net dehydration rate.

[0027] The upper limit of the baseline net dehydration rate is determined by multiplying it by the fixed reduction factor, thereby establishing the upper limit of the net dehydration rate for the current cycle. In this way, the upper limit of the net dehydration rate is not only related to the patient's weight but can also be dynamically reduced based on hemodynamic status, thus achieving a safety constraint that matches the patient's immediate hemodynamic state. Simultaneously, the system, in conjunction with a preset lower limit of the net dehydration rate and the upper limit, determines the hard boundary of the net dehydration rate. The lower limit of the net dehydration rate is used to define the minimum permissible value of the net dehydration rate, forming an inviolable control boundary together with the upper limit.

[0028] Through the above embodiments, this invention introduces a dual constraint mechanism based on patient weight and hemodynamic grade in the CRRT fluid management decision-making process, forming a clear hard boundary for the net dehydration rate. This hard boundary provides a deterministic safety range for the generation, trimming, and execution of subsequent net dehydration instructions, ensuring that the CRRT device is always constrained by a control boundary that matches the patient's current physiological state when performing fluid removal operations, thereby enhancing the safety and controllability of the fluid management decision-making process.

[0029] In one embodiment of the present invention, reading the target cumulative net dehydration amount and the completed cumulative net dehydration amount to determine the net dehydration command, and hard-cutting the net dehydration command according to the net dehydration rate boundary, includes: Step 31: Read the target cumulative net dehydration amount and the completed cumulative net dehydration amount. The target cumulative net dehydration amount is a pre-set target value in the treatment prescription, used to characterize the total net dehydration amount expected to be completed in this stage of CRRT treatment; the completed cumulative net dehydration amount is the net dehydration amount actually completed in real time during the treatment process. The system determines the difference between the target cumulative net dehydration amount and the completed cumulative net dehydration amount as the remaining net dehydration amount, which is used to characterize the net dehydration target that still needs to be completed in subsequent treatment processes.

[0030] Step 32: After determining the remaining net dehydration amount, a theoretical net dehydration command is further generated. Specifically, the remaining net dehydration amount is used as the numerator, and the time period corresponding to the preset acquisition cycle is used as the denominator. The ratio of the numerator to the denominator is calculated to obtain the theoretical net dehydration command. The time period corresponding to the preset acquisition cycle is a fixed time length between two adjacent net dehydration command updates in the system control loop, used to convert the remaining net dehydration amount into a target net dehydration rate per unit time. In this way, the theoretical net dehydration command reflects the net dehydration rate required, under ideal conditions, to uniformly complete the remaining net dehydration target within the current acquisition cycle.

[0031] Step 33: While generating the theoretical net dehydration command, the system reads the lower and upper limits of the net dehydration rate hard boundary. These limits together define the range of net dehydration rates that the CRRT equipment is allowed to execute within the current cycle. Subsequently, the system compares the theoretical net dehydration command with these limits. When the theoretical net dehydration command is less than the lower limit, the system determines the command as the lower limit; when it is greater than the upper limit, it determines the command as the upper limit; and when it falls between these limits, it is determined as the theoretical net dehydration command. Finally, the system outputs the determined net dehydration command as the target control quantity subsequently written into the CRRT equipment's net ultrafiltration control channel.

[0032] Through the above implementation methods, this invention transforms the cumulative net dehydration requirement at the treatment target level into a net dehydration command that matches the control cycle of the CRRT device. This command is then subject to a hard boundary constraint on the net dehydration rate, ensuring that the dehydration process continuously converges towards the target cumulative net dehydration volume without exceeding the safe range defined by hemodynamic status and individual patient characteristics. This net dehydration command generation and pruning mechanism provides a definite and executable control input for subsequent CRRT fluid management decisions, improving treatment efficiency and hemodynamic stability during continuous blood purification.

[0033] In one embodiment of the present invention, a net dehydration command is written into the net ultrafiltration control channel of the CRRT device, keeping the total removal dose constant, and when net dehydration and total removal dose are not completely decoupled, the replacement fluid flow rate and dialysate flow rate are determined based on the total removal dose and the net dehydration command, including: Step 41: Read the net dehydration command output from the preceding steps and the total clearance dose set in the treatment prescription. The net dehydration command is the desired net dehydration rate control quantity per unit time, used to control the fluid removal process of the CRRT device; the total clearance dose is a prescription parameter used to characterize the overall solute clearance intensity achieved per unit time through dialysis and replacement processes. The system writes the net dehydration command into the net ultrafiltration control channel of the CRRT device. The net ultrafiltration control channel is the control interface in the CRRT device used to receive and execute the net dehydration rate control quantity, and its controlled object is the ultrafiltration execution unit of the device. While writing the net dehydration command, the system keeps the total clearance dose as a fixed constraint quantity, thereby ensuring that the solute clearance intensity does not deviate due to fluid management adjustments.

[0034] Step 42: Read the control mode configuration of the CRRT device and determine whether the current control mode is the total clearance dose linkage mode. The control mode configuration refers to the configuration parameters in the CRRT device used to describe the relationship between net dehydration control and clearance dose control. When the control mode is configured as the total clearance dose linkage mode, it indicates that there is a linkage relationship between net dehydration adjustment and clearance dose. The total clearance dose linkage mode refers to a control mode configuration of the CRRT device. In this control mode, changes in the net dehydration command will constrain the allocatable range or target setting of the replacement fluid flow rate and dialysate flow rate. Furthermore, while maintaining the total clearance dose unchanged, the replacement fluid flow rate and dialysate flow rate need to be adjusted in linkage according to the net dehydration command. In this case, the system determines that net dehydration and total clearance dose are not completely decoupled, and further calculates the difference between the total clearance dose and the net dehydration command to obtain the clearance dose difference. The clearance dose difference is used to characterize the total clearance dose that still needs to be achieved through dialysate and replacement fluid after deducting the amount of fluid removed corresponding to net dehydration.

[0035] Step 43: After determining the clearance dose difference, the system limits the sum of the replacement fluid flow rate and the dialysate flow rate to the clearance dose difference. Subsequently, the system determines the proportional relationship between the replacement fluid flow rate and the dialysate flow rate based on the initial values ​​of the replacement fluid flow rate and the dialysate flow rate in the prescription parameters. These initial values ​​are initial control parameters set at the start of treatment, characterizing the relative distribution ratio of the two fluid pathways during dialysis. While maintaining this proportional relationship, the system adjusts the initial values ​​of the replacement fluid flow rate and the dialysate flow rate proportionally, so that the sum of the adjusted replacement fluid flow rate and the adjusted dialysate flow rate equals the clearance dose difference. Finally, the system writes the adjusted replacement fluid flow rate and the adjusted dialysate flow rate into the replacement fluid channel and the dialysate channel of the CRRT device, respectively, so that the corresponding fluid pathways operate according to the new settings.

[0036] Through the above embodiments, this invention, while executing the net dehydration command, can simultaneously adjust the flow rates of the replacement fluid and dialysate in a device control mode where net dehydration and total clearance dose are not completely decoupled, thereby achieving the fluid management goal while maintaining a stable total clearance dose. This control mechanism enables the fluid removal and solute clearance processes of the CRRT device to operate in a coordinated manner within the same control framework, helping to avoid clearance dose fluctuations caused by adjusting net dehydration alone, and improving the coordination between fluid management and hemodynamic stability during continuous blood purification treatment.

[0037] In one embodiment of the present invention, when the hemodynamic level meets preset conditions, a safe mode is entered, the net dehydration command is set to zero and the safe mode fluid resuscitation volume is executed, the number of observation cycles is locked in the continuous safe mode, and the safe mode is deactivated and the net dehydration command is updated after the threshold for the number of recovery trigger cycles is met, including: Step 51: Continuously read the hemodynamic level determined in the preceding steps. When the hemodynamic level is at a dangerous level, or when the hemodynamic level is at a restricted level and reaches a preset number of cycles consecutively, the system determines that the patient's current hemodynamic state has a significant risk of restriction, and thus enters a safe mode. The preset number of cycles is a counting threshold used to determine the persistence of hemodynamic abnormalities, used to avoid triggering unnecessary safe modes due to short-term fluctuations. After entering safe mode, the system sets the net dehydration command to zero and writes the zeroed net dehydration command into the net ultrafiltration control channel of the CRRT device. The net ultrafiltration control channel is the control interface in the CRRT device used to receive and execute the net dehydration rate control quantity. By setting the net dehydration command to zero, further fluid removal operations can be stopped immediately.

[0038] Step 52: After entering safe mode, the system further executes the safe mode fluid resuscitation volume. This safe mode fluid resuscitation volume is a pre-set or configured fluid control volume, used to replenish a certain amount of fluid to the patient in safe mode to alleviate potential circulatory volume insufficiency. Simultaneously, the system counts the number of safe mode locked observation periods, using a preset acquisition cycle as the counting unit. This number of safe mode locked observation periods is the minimum number of observation periods that must be maintained in safe mode, used to continuously monitor hemodynamic status within a certain time window and avoid premature termination of safe mode. During the locked observation phase, the system continuously writes the zeroed net dehydration command into the net ultrafiltration control channel of the CRRT device, thereby ensuring that net dehydration operation is not resumed during this phase.

[0039] Step 53: After the safety mode lock observation period count is completed, the system enters the safety mode release determination stage. Specifically, the system continuously reads the hemodynamic level and counts the number of consecutive periods with a hemodynamic level of stable or slightly restricted, using a preset acquisition period as the counting unit. The stable or slightly restricted level indicates that the hemodynamic state has returned to a relatively safe or slightly restricted range. When the number of consecutive periods reaches the recovery trigger period threshold, the system determines that the hemodynamic state has continuously improved, thereby releasing the safety mode. After releasing the safety mode, the system calls the dehydration instruction module to generate and trim the net dehydration instruction, recalculates and trims the net dehydration instruction, and writes the updated net dehydration instruction into the net ultrafiltration control channel of the CRRT device to restore net dehydration control under safety constraints.

[0040] Through the above implementation methods, this invention constructs a safety mode state machine based on hemodynamic levels in the CRRT fluid management decision-making process, realizing closed-loop control of safety mode entry, locking observation, and unlocking / updating. This mechanism enables the net dehydration operation to be promptly suppressed when the hemodynamic state deteriorates and to be orderly restarted after the state stabilizes and recovers, helping to balance fluid removal needs and hemodynamic safety during continuous blood purification treatment.

[0041] In one embodiment of the present invention, in order to uniformly handle the completion status of treatment goals and the abnormal persistence status during CRRT treatment, the system is equipped with a termination takeover module, which is used to output a stop control command or a manual takeover flag when preset conditions are met, so that the CRRT fluid management process can achieve a clear and orderly switch between automatic control and manual intervention.

[0042] Specifically, the termination module first reads the completed cumulative net dehydration volume and the target cumulative net dehydration volume. The system compares the completed cumulative net dehydration volume with the target cumulative net dehydration volume. When the completed cumulative net dehydration volume reaches the target cumulative net dehydration volume, the system determines that the current stage of net dehydration has been completed, and thus outputs a stop control command. At the same time, the system sets the net dehydration command to zero and writes the zeroed net dehydration command to the net ultrafiltration control channel of the CRRT equipment. In this way, further net dehydration operations can be terminated in a timely manner when the target cumulative net dehydration volume is reached, preventing excessive liquid removal.

[0043] Beyond the aforementioned termination logic, the termination takeover module also handles persistent abnormal situations in safe mode. Specifically, the system reads the safe mode status and the number of safe mode lock observation periods. The safe mode is a restricted control state entered when hemodynamic conditions deteriorate; when the system determines it is in safe mode, and the safe mode has persisted for the required number of safe mode lock observation periods without being deactivated, the system outputs a manual takeover flag. This flag indicates that medical personnel need to manually intervene in the CRRT device's operation and treatment strategy to address abnormal situations that automatic control cannot handle further.

[0044] Through the above implementation methods, this invention establishes a clear termination and takeover mechanism in the CRRT fluid management decision-making process. On the one hand, when the target cumulative net dehydration volume is achieved, the system can automatically terminate the net dehydration operation, ensuring that the treatment process is strictly controlled within the preset target. On the other hand, if the safe mode persists and cannot be automatically deactivated, the system can promptly output a manual takeover signal to guide manual intervention, thereby avoiding the risks of automatic control being in a restricted state for an extended period. This termination and takeover module creates a clear boundary between automatic control and manual decision-making in the CRRT fluid management decision-making system, enhancing the safety and controllability of the continuous blood purification treatment process.

[0045] In one embodiment of the present invention, the blood flow acquisition module further includes triggering baseline dataset updates based on continuous counting of hemodynamic levels, including: Step 61: During CRRT treatment, continuously read the hemodynamic grade output from the preceding steps, and count the number of consecutive cycles with a stable hemodynamic grade, using a preset acquisition cycle as the counting unit. The stable grade indicates that the hemodynamic state is in a relatively stable range. By counting the number of consecutive cycles with a stable grade, the system can identify situations where the patient's hemodynamic state remains stable over a period of time, thereby providing a trigger for baseline updates.

[0046] Step 62: When the number of consecutive cycles with the hemodynamic level at the stable level reaches the baseline acquisition cycle count threshold, the system triggers a baseline update. The baseline acquisition cycle count threshold is a pre-set counting threshold used to limit the minimum stable duration required to trigger a baseline update, thus avoiding frequent updates caused by short-term stability fluctuations. After triggering the baseline update, the system determines the acquisition record corresponding to the trigger time as the baseline update start point. The baseline update start point is used to define the starting position of the data referenced in the new round of baseline data calculation, thereby ensuring that the baseline update process has a clear time anchor point.

[0047] Step 63: After determining the baseline update starting point, the system re-executes the stable acquisition cycle determination process based on this baseline update starting point, and updates the baseline dataset accordingly. The specific process is consistent with the aforementioned baseline dataset construction process, that is, in the current hemodynamic dataset after the baseline update starting point, stable acquisition cycles that meet the stability determination criteria are re-selected, and the corresponding representative values ​​of systolic blood pressure, mean arterial pressure, and heart rate are calculated to form a new baseline dataset to replace the previous baseline dataset.

[0048] Through the above implementation methods, this invention introduces a baseline self-updating mechanism based on continuous and stable counting of hemodynamic grades into the CRRT fluid management decision system, enabling the hemodynamic baseline data to be dynamically adjusted according to the phased changes in the patient's condition. This mechanism ensures that subsequent calculations of hemodynamic change rates, grade determinations, and net dehydration control decisions are always based on a reference benchmark that matches the patient's current stable state, thereby improving the adaptability and consistency of fluid management decisions.

[0049] This invention also provides a CRRT fluid management decision-making method based on hemodynamic monitoring, comprising the following steps: Step 71: Collect systolic blood pressure, mean arterial pressure, and heart rate to form the current hemodynamic dataset, and determine the baseline dataset based on the stable acquisition cycle; Step 72: Calculate the relative change rate of mean arterial pressure and the heart rate-systolic pressure ratio based on the current hemodynamic dataset and the baseline dataset, and match them with a preset fixed threshold table to obtain the hemodynamic level; Step 73: Determine the hard boundary of net dehydration rate based on hemodynamic grade and patient weight; Step 74: Read the target cumulative net dehydration amount and the completed cumulative net dehydration amount to determine the net dehydration command, and cut the net dehydration command according to the hard boundary of the net dehydration rate; Step 75: Write the net dehydration command into the net ultrafiltration control channel of the CRRT device, keep the total removal dose constant, and determine the replacement fluid flow rate and dialysate flow rate based on the total removal dose and the net dehydration command when the net dehydration and total removal dose are not completely decoupled. Step 76: When the hemodynamic level meets the preset conditions, enter the safety mode, set the net dehydration command to zero and execute the safety mode fluid resuscitation volume, lock the observation period number in the continuous safety mode, and release the safety mode and update the net dehydration command after the recovery trigger period number threshold is met. Step 77: When the cumulative net dehydration amount reaches the target cumulative net dehydration amount, output a stop control command and set the net dehydration command to zero. When in safe mode and the safe mode is not released within the number of safe mode lock observation periods, output a manual takeover flag.

[0050] It should be noted that the interval and threshold sizes are set for ease of comparison. The size of the threshold depends on the amount of sample data and the base number set by those skilled in the art for each set of sample data, as long as it does not affect the proportional relationship between the parameter and the quantized value. Furthermore, the above formulas are all dimensionless calculations, and the formulas are derived from software simulations using a large amount of collected data to obtain the most recent real-world results. The preset parameters in the formulas are set by those skilled in the art according to the actual situation.

[0051] The embodiments of the present invention have been described above, but the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms based on the guidance of the present embodiments, all of which are within the protection scope of the present embodiments.

Claims

1. A CRRT fluid management decision system based on hemodynamic monitoring, characterized in that, include: The blood flow acquisition module is used to acquire systolic blood pressure, mean arterial pressure, and heart rate to form the current hemodynamic dataset, and to determine the baseline dataset based on a stable acquisition cycle; The grading module is used to calculate the relative change rate of mean arterial pressure and the heart rate-systolic pressure ratio based on the current hemodynamic dataset and the baseline dataset, and match them with a preset fixed threshold table to obtain the hemodynamic grade. The dehydration boundary module is used to determine the hard boundary of the net dehydration rate based on hemodynamic grade and patient weight; The dehydration instruction module is used to read the target cumulative net dehydration amount and the completed cumulative net dehydration amount to determine the net dehydration instruction, and to hard-cut the net dehydration instruction according to the net dehydration rate. The pump control linkage module is used to write the net dehydration command into the net ultrafiltration control channel of the CRRT equipment, keep the total removal dose constant, and determine the replacement fluid flow rate and dialysate flow rate according to the total removal dose and the net dehydration command when the net dehydration and total removal dose are not completely decoupled. The safety control module is used to enter the safety mode when the hemodynamic level meets the preset conditions, set the net dehydration command to zero and execute the fluid replacement volume in the safety mode, lock the observation period number in the continuous safety mode, and release the safety mode and update the net dehydration command after the recovery trigger period number threshold is met. The termination takeover module is used to output a stop control command and set the net dehydration command to zero when the cumulative net dehydration amount reaches the target cumulative net dehydration amount. When in safe mode and the safe mode is not released within the number of safe mode lock observation periods, it outputs a manual takeover flag.

2. The CRRT fluid management decision system based on hemodynamic monitoring of claim 1, wherein, Systolic blood pressure, mean arterial pressure, and heart rate are collected to form the current hemodynamic dataset, and a baseline dataset is determined based on a stable acquisition cycle, including: Step 11: Collect systolic blood pressure, mean arterial pressure, and heart rate according to the preset collection cycle, and combine the systolic blood pressure, mean arterial pressure, and heart rate obtained from each collection with the collection timestamp to form a collection record, and write it into the current hemodynamic dataset in increments according to the collection timestamp; Step 12: Extract continuous acquisition records from the current hemodynamic dataset according to the baseline acquisition cycle number threshold to form candidate windows. Take the maximum and minimum values ​​of systolic blood pressure within the candidate window and obtain the systolic blood pressure fluctuation value by the difference between the two. Take the maximum and minimum values ​​of mean arterial pressure within the candidate window and obtain the mean arterial pressure fluctuation value by the difference between the two. Take the maximum and minimum values ​​of heart rate within the candidate window and obtain the heart rate fluctuation value by the difference between the two. Compare the systolic blood pressure fluctuation value, mean arterial pressure fluctuation value, and heart rate fluctuation value with their respective stability determination thresholds. When all three do not exceed the corresponding stability determination thresholds, the corresponding candidate window is determined as a stable acquisition cycle. Step 13: For the acquisition records within the stable acquisition period, sum the acquired systolic blood pressure values ​​and divide by the number of acquisition values ​​to obtain the representative systolic blood pressure value; sum the acquired mean arterial pressure values ​​and divide by the number of acquisition values ​​to obtain the representative mean arterial pressure value; sum the acquired heart rate values ​​and divide by the number of acquisition values ​​to obtain the representative heart rate value; and write the representative systolic blood pressure value, representative mean arterial pressure value, representative heart rate value, and stable acquisition period identifier into the baseline dataset.

3. The CRRT fluid management decision system based on hemodynamic monitoring of claim 1, wherein, Based on the current hemodynamic dataset and the baseline dataset, the relative rate of change of mean arterial pressure and the heart rate-systolic pressure ratio are calculated and matched with a preset fixed threshold table to obtain the hemodynamic grade, including: Step 21: Select the acquisition record corresponding to the latest acquisition timestamp in the current hemodynamic dataset as the acquisition record for this cycle, and extract the current systolic blood pressure, current mean arterial pressure, and current heart rate from the acquisition record for this cycle. At the same time, extract the baseline mean arterial pressure from the baseline dataset. Step 22: Use the difference between the baseline mean arterial pressure and the current mean arterial pressure as the numerator and the baseline mean arterial pressure as the denominator, and calculate the ratio of the numerator to the denominator to obtain the relative rate of change of mean arterial pressure; use the current heart rate as the numerator and the current systolic pressure as the denominator, and calculate the ratio of the numerator to the denominator to obtain the heart rate-systolic pressure ratio. Step 23: Compare the relative change rate of mean arterial pressure with the threshold intervals of the relative change rate of mean arterial pressure in the preset fixed threshold table one by one, and compare the heart rate-systolic pressure ratio with the threshold intervals of the heart rate-systolic pressure ratio in the preset fixed threshold table one by one. When the relative change rate of mean arterial pressure and the heart rate-systolic pressure ratio both fall into the threshold interval corresponding to the same entry, output the hemodynamic level corresponding to that entry. The hemodynamic levels include: stable level, mildly restricted level, restricted level, and dangerous level.

4. The CRRT fluid management decision system based on hemodynamic monitoring of claim 1, wherein, The dehydration boundary module includes: Obtain the patient's weight and determine the upper limit of the basic net dehydration rate by multiplying the patient's weight by a fixed coefficient; Based on the hemodynamic grade, the fixed reduction factor is retrieved from the correspondence table between hemodynamic grade and fixed reduction factor. The product of the upper limit of the baseline net dehydration rate and the fixed reduction factor is determined as the upper limit of the net dehydration rate. The lower limit of the net dehydration rate and the upper limit of the net dehydration rate are jointly determined as the hard boundary of the net dehydration rate.

5. The CRRT fluid management decision system based on hemodynamic monitoring of claim 1, wherein, The system reads the target cumulative net dehydration volume and the completed cumulative net dehydration volume to determine the net dehydration command, and then hard-cuts the net dehydration command according to the net dehydration rate, including: Step 31: Read the target cumulative net dehydration amount and the completed cumulative net dehydration amount, and determine the difference between the target cumulative net dehydration amount and the completed cumulative net dehydration amount as the remaining net dehydration amount; Step 32: Take the remaining net dehydration amount as the numerator and the time period corresponding to the preset collection cycle as the denominator, calculate the ratio of the numerator to the denominator to obtain the theoretical net dehydration command, and read the lower limit and upper limit of the net dehydration rate in the hard boundary of the net dehydration rate. Step 33: When the theoretical net dehydration command is less than the lower limit of the net dehydration rate, the net dehydration command is determined as the lower limit of the net dehydration rate; when the theoretical net dehydration command is greater than the upper limit of the net dehydration rate, the net dehydration command is determined as the upper limit of the net dehydration rate; when the theoretical net dehydration command is between the lower limit and the upper limit of the net dehydration rate, the net dehydration command is determined as the theoretical net dehydration command, and the net dehydration command is output.

6. The CRRT fluid management decision system based on hemodynamic monitoring of claim 1, wherein, The net dehydration command is written into the net ultrafiltration control channel of the CRRT device, keeping the total removal dose constant. When net dehydration and total removal dose are not completely decoupled, the replacement fluid flow rate and dialysate flow rate are determined based on the total removal dose and the net dehydration command, including: Step 41: Read the net dehydration command and total removal dose, and write the net dehydration command into the net ultrafiltration control channel of the CRRT device, while keeping the total removal dose unchanged; Step 42: Read the control mode configuration of the CRRT device and determine whether the control mode configuration is the total removal dose linkage mode; when the control mode configuration is the total removal dose linkage mode, it is determined that the net dehydration and the total removal dose are not completely decoupled. At this time, the difference between the total removal dose and the net dehydration command is calculated to obtain the removal dose difference value. Step 43: The sum of the replacement fluid flow rate and the dialysate flow rate is determined as the clearance dose difference. Based on the initial values ​​of the replacement fluid flow rate and the dialysate flow rate in the prescription parameters, the ratio between the replacement fluid flow rate and the dialysate flow rate is determined. While keeping the ratio unchanged, the initial values ​​of the replacement fluid flow rate and the dialysate flow rate are adjusted proportionally so that the sum of the adjusted replacement fluid flow rate and the adjusted dialysate flow rate equals the clearance dose difference. The adjusted replacement fluid flow rate and the adjusted dialysate flow rate are then written into the replacement fluid channel and the dialysate channel of the CRRT device, respectively.

7. The CRRT fluid management decision system based on hemodynamic monitoring of claim 1, wherein, When the hemodynamic level meets preset conditions, the system enters safe mode, the net dehydration command is set to zero, and the safe mode fluid resuscitation volume is executed. The number of observation cycles is locked in continuous safe mode. Once the threshold for the recovery trigger cycle number is met, the safe mode is deactivated, and the net dehydration command is updated, including: Step 51: Read the hemodynamic level. When the hemodynamic level is dangerous or restricted for a number of consecutive cycles, enter the safety mode, set the net dehydration command to zero, and write the zeroed net dehydration command into the net ultrafiltration control channel of the CRRT device. Step 52: After entering the safe mode, execute the safe mode liquid replenishment volume, and count the number of safe mode lock observation cycles using the preset collection cycle as the counting unit. Before the count reaches the number of safe mode lock observation cycles, continuously write the net dehydration command after zeroing into the net ultrafiltration control channel of the CRRT equipment. Step 53: After the count reaches the number of observation cycles locked in the safe mode, the hemodynamic level is continuously read and the number of consecutive cycles with the hemodynamic level of stable or slightly restricted is counted using the preset collection cycle as the counting unit. When the number of consecutive cycles reaches the threshold of the number of recovery trigger cycles, the safe mode is deactivated, and the process of generating and trimming the net dehydration command by calling the dehydration command module is updated and written into the net ultrafiltration control channel of the CRRT device.

8. The CRRT fluid management decision system based on hemodynamic monitoring of claim 1, wherein, The termination takeover module includes: Read the completed cumulative net dehydration amount and the target cumulative net dehydration amount. When the completed cumulative net dehydration amount reaches the target cumulative net dehydration amount, output a stop control command, set the net dehydration command to zero, and write the zeroed net dehydration command into the net ultrafiltration control channel of the CRRT equipment. Read the number of observation periods for the safe mode and the safe mode lock. When the device is in safe mode and the number of observation periods for the safe mode lock is reached without deactivating the safe mode, output a manual takeover flag.

9. The CRRT fluid management decision system based on hemodynamic monitoring of claim 1, wherein, The blood flow acquisition module also includes baseline dataset updates triggered by continuous counting based on hemodynamic levels, including: Step 61: Continuously read the hemodynamic level and count the number of consecutive cycles with a stable hemodynamic level using a preset acquisition cycle as the counting unit. Step 62: When the number of consecutive cycles reaches the baseline acquisition cycle number threshold, a baseline update is triggered, and the acquisition record corresponding to the triggering time of the baseline update is taken as the starting point of the baseline update. Step 63: After triggering the baseline update, redetermine the stable acquisition period based on the baseline update start point and update the baseline dataset.

10. A CRRT fluid management decision method based on hemodynamic monitoring, characterized in that, The CRRT fluid management decision system based on hemodynamic monitoring as described in any one of claims 1-9 includes the following steps: Step 71: Collect systolic blood pressure, mean arterial pressure, and heart rate to form the current hemodynamic dataset, and determine the baseline dataset based on the stable acquisition cycle; Step 72: Calculate the relative change rate of mean arterial pressure and the heart rate-systolic pressure ratio based on the current hemodynamic dataset and the baseline dataset, and match them with a preset fixed threshold table to obtain the hemodynamic level; Step 73: Determine the hard boundary of net dehydration rate based on hemodynamic grade and patient weight; Step 74: Read the target cumulative net dehydration amount and the completed cumulative net dehydration amount to determine the net dehydration command, and cut the net dehydration command according to the hard boundary of the net dehydration rate; Step 75: Write the net dehydration command into the net ultrafiltration control channel of the CRRT device, keep the total removal dose constant, and determine the replacement fluid flow rate and dialysate flow rate based on the total removal dose and the net dehydration command when the net dehydration and total removal dose are not completely decoupled. Step 76: When the hemodynamic level meets the preset conditions, enter the safety mode, set the net dehydration command to zero and execute the safety mode fluid resuscitation volume, lock the observation period number in the continuous safety mode, and release the safety mode and update the net dehydration command after the recovery trigger period number threshold is met. Step 77: When the cumulative net dehydration amount reaches the target cumulative net dehydration amount, output a stop control command and set the net dehydration command to zero. When in safe mode and the safe mode is not released within the number of safe mode lock observation periods, output a manual takeover flag.

Images