Ultrafiltration control in extracorporeal blood treatment

Abstract

A control system operates (201) an apparatus for extracorporeal blood treatment to extract, treat and return blood of an individual while removing fluid from the blood according to a set value of an ultrafiltration rate UFR. The control system also obtains (202) sensor data representing one or more physiological parameters of the individual and intermittently performs an optimization procedure (203) to generate the set value based on the sensor data. The optimization procedure includes evaluating (203A) the sensor data for detecting a limiting physiological state LPS, sequentially controlling (203B) the apparatus according to a test sequence of UFRs until a LPS is detected for a current UFR, and updating (203C) the set value based on the current UFR for operating the apparatus after the optimization procedure. The system can perform a series of optimization procedures at time intervals during a treatment session to adapt the UFR to the individual.

Description

Technical Field

[0001] This disclosure generally relates to extracorporeal blood processing, wherein blood is drawn from an individual, pumped through a blood filter device and returned to the individual, and in particular, to a control system and method for setting an ultrafiltration rate to be achieved in the blood filter device. Background Technology

[0002] Many extracorporeal kidney replacement procedures involve extracorporeal blood processing, which is typically used to provide replacement or supplementation of an individual's natural kidney function in order to remove fluids and / or waste products from the individual's blood. These procedures ("treatment procedures") include, for example, hemodialysis, hemofiltration, hemodiafiltration, and plasmapheresis. All of these procedures involve, or may involve, the extraction and removal of fluids from the blood during treatment. The extracted fluids include plasma water and may also include some solutes dissolved in the plasma water. Fluid extraction is often referred to as "ultrafiltration" (UF) and can be performed by establishing a pressure gradient across a porous or semi-permeable filter to drive the fluid along the established pressure gradient through the filter.

[0003] Extracorporeal blood processing is performed by a dedicated device based on settings that are at least partially entered by caregivers or operators before the start of the treatment. Typically, the individual is weighed before the treatment, and the total volume of fluid to be extracted and removed (total UF) is calculated by subtracting the individual's estimated "dry weight" from the current weight. The total UF and the duration of the treatment can be entered into the device's control system, which can then determine, among other control parameters, the fluid extraction rate (UF rate), which will be applied by the device during blood processing. The UF rate can be set as a constant value given by dividing the total UF by the duration, or it can vary according to a predetermined profile.

[0004] Complications (also known as dialysis complications) caused by the extraction of large amounts of fluid from an individual's blood during extracorporeal blood processing are not uncommon. One such complication is symptomatic hypotension, which involves a sudden drop in blood pressure and symptoms such as cramps, nausea, vomiting, and sometimes fainting. Hypotension episodes are not only distressing for the individual but also require considerable attention from staff monitoring the treatment.

[0005] One potential cause of hypotension is an overestimation of total fluid volume (UF) during treatment, as weight gain exceeding dry weight does not necessarily have to be attributed entirely to fluid accumulation. Furthermore, the determination of total UF does not account for the internal distribution of accumulated fluid within the individual, such as the relationship between intracellular and extracellular fluid, which may affect the amount of fluid that can be extracted without increasing the risk of hypotension. Moreover, an individual's physiological response to fluid extraction may vary during treatment.

[0006] Besides hypotension, other dialysis complications that may occur during extracorporeal blood processing include nausea, vomiting, fever, chills, headache, cramps, chest pain, back pain, hypoglycemia, first-use syndrome, and femoral hematoma. At least some of these dialysis complications can be attributed, at least in part, to fluid aspiration.

[0007] There is a need for an automated technology to control equipment used for extracorporeal blood processing in order to reduce the risk of complications during dialysis while ensuring effective blood processing.

[0008] Prior art includes patent document US2007 / 0215545, which discloses a method for continuously optimizing the UF rate during in vitro kidney replacement by receiving patient physiological data and UF rate data and mapping this data to a mathematical prediction model, which generates predicted states for model parameters. Based on the predicted states, the UF rate is increased, maintained, or decreased. Therefore, the UF rate is continuously evaluated and adjusted in real time.

[0009] This real-time adjustment technique is highly dependent on the accuracy and response time of the predictive model. However, the physiological response to changes in UF rate can vary between individuals, between different UF rates, between different treatment procedures, and between different directions of UF rate change. Summary of the Invention

[0010] The aim is to at least partially overcome one or more limitations in the existing technology.

[0011] One objective is to provide a robust and automated technique for controlling devices used for extracorporeal blood processing to reduce the risk of complications during dialysis while ensuring at least as effective blood processing as ultrafiltration.

[0012] Another objective is to simplify the setup of equipment used for extracorporeal blood processing.

[0013] One or more of these objectives, and other objectives that may emerge from the following description, are achieved, at least in part, by a control system for an extracorporeal blood processing device, an extracorporeal blood processing device, a method, and a computer-readable medium, embodiments of which are defined by the dependent claims.

[0014] A first aspect of this disclosure is a control system for an extracorporeal blood processing device. The control system includes: logic circuitry configured to control the extracorporeal blood processing device during treatment to draw blood from an individual, pump the blood through a blood filter device and return it to the individual, while simultaneously removing fluid from the blood in the blood filter device according to a set value of an ultrafiltration rate; and inputs for sensor data representing one or more physiological parameters of the individual. The logic circuitry is also configured to intermittently perform an optimization process during treatment to generate set values ​​based on the sensor data. The optimization process includes: evaluating the sensor data to detect limiting physiological states of the individual; sequentially controlling the extracorporeal blood processing device to achieve corresponding ultrafiltration rates in a sequence of different ultrafiltration rates until the evaluation detects a limiting physiological state for the current ultrafiltration rate; and updating the set values ​​based on the current ultrafiltration rate to continue the treatment after the optimization process.

[0015] An optimization process is executed according to the control system of the first aspect, which effectively controls the blood processing device to sequentially pass through a sequence of different ultrafiltration rates while monitoring the individual's physiological response as given by sensor data. Therefore, the sequence of ultrafiltration rates forms a test or calibration sequence for assessing the individual's current acceptance of the ultrafiltration rate and identifying appropriate setpoints for the ultrafiltration rate to prevent or reduce negative impacts on the individual's health. The optimization process is interrupted whenever the assessment of the sensor data detects a restrictive physiological state in the individual, thereby avoiding placing significant physiological stress on the individual. A restrictive physiological state may correspond to an individual being detectably affected by the ultrafiltration rate while not yet suffering from serious symptoms (such as any dialysis complications discussed in the background section).

[0016] Therefore, the optimization process can be viewed as an intermittent and structured test performed during the treatment course, leading to an update of the setpoints to be used when the course continues after the optimization process. The optimization process can be performed at the start of the course or at any time thereafter. The structured optimization process allows the control system to objectively determine the individual's current sensitivity to the ultrafiltration rate at any time during the course and to generate an appropriate setpoint for the ultrafiltration rate. Thus, the control system of the first aspect provides a robust, objective, and automated technique for controlling extracorporeal blood processing by adapting the ultrafiltration rate to the individual in order to reduce the risk of complications during dialysis. Simultaneously, because the optimization process explores the current upper limit of the ultrafiltration rate relevant to the individual, the control system of the first aspect can control the blood processing equipment to achieve a higher ultrafiltration rate, for example, at or near that current upper limit, thereby ensuring effective blood processing.

[0017] Below, various embodiments of the first aspect are defined. These embodiments provide at least some of the technical effects and advantages previously described, as well as additional technical effects and advantages that are readily understood by those skilled in the art, for example, from the following detailed description.

[0018] In some embodiments, the evaluation includes: obtaining sensor data for a given ultrafiltration rate, wherein obtaining the sensor data for the given ultrafiltration rate is time-separated from establishing the given ultrafiltration rate at the extracorporeal blood processing device by a stable time interval.

[0019] In some embodiments, sequences of different ultrafiltration rates are sorted by increasing the magnitude starting from the minimum value.

[0020] In some embodiments, the optimization process further includes setting a setpoint to a predetermined value below the minimum if sensor data indicates a restrictive physiological state for the minimum.

[0021] In some embodiments, the predetermined value corresponds to an ultrafiltration rate of zero.

[0022] In some embodiments, the control system is configured to perform at least two optimization processes during the treatment, wherein the minimum value is equal in at least two optimization processes.

[0023] In some embodiments, a restrictive physiological state is defined as an undesirable physiological state for an individual.

[0024] In some embodiments, a restrictive physiological state is defined as avoiding complications during an individual's dialysis.

[0025] In some embodiments, the control system is further configured to obtain corresponding initial values ​​of one or more physiological parameters from sensor data during a calibration period, and to define a restrictive physiological state based on the corresponding initial values.

[0026] In some embodiments, the calibration period is before the treatment or at the start of the treatment.

[0027] In some embodiments, one or more physiological parameters include at least one of vital signs, blood volume, or cardiac output.

[0028] In some embodiments, vital signs include one or more of the following: heart rate, blood pressure, blood oxygen saturation level, respiratory rate, skin temperature, skin color, urine output, mental status, capillary refill time, a measure of electrolyte balance in an individual, or a measure of acid-base balance in an individual.

[0029] In some embodiments, the control system is configured to autonomously initiate an optimization process during the treatment.

[0030] In some embodiments, the control system is configured to initiate an optimization process based on one or any combination of the following conditions: a predetermined time interval to the previous optimization process, or based on sensor data, or based on a set value generated by the previous optimization process.

[0031] In some embodiments, the predetermined time interval at the end of the treatment is shorter than the predetermined time interval at the beginning of the treatment.

[0032] In some embodiments, the control system is configured to perform a series of time-separated optimization processes during the treatment.

[0033] In some embodiments, the control system is also configured to receive a user-defined duration value and set the duration of the treatment to the user-defined duration value.

[0034] A second aspect of this disclosure is an extracorporeal blood processing device. The device includes: a pumping device operable to draw blood from an individual and pump the blood through a blood filtering device and return it to the individual, while simultaneously removing fluid from the blood in the blood filtering device at an ultrafiltration rate; and a control system of the first aspect or any embodiment thereof.

[0035] A third aspect of this disclosure is a method for operating a control system for an extracorporeal blood processing device during a treatment procedure. The method includes: during the treatment procedure, controlling the extracorporeal blood processing device to draw blood from an individual through a blood filter device and pump the blood back to the individual, while simultaneously removing fluid from the blood in the blood filter device according to a set value of an ultrafiltration rate; obtaining sensor data representing one or more physiological parameters of the individual; and intermittently performing an optimization process during the treatment procedure to generate the set value based on the sensor data. The optimization process includes: evaluating the sensor data to detect limiting physiological states of the individual; sequentially controlling the extracorporeal blood processing device to achieve corresponding ultrafiltration rates in a sequence of different ultrafiltration rates until the evaluation detects a limiting physiological state for the current ultrafiltration rate; and updating the set value based on the current ultrafiltration rate to continue the treatment procedure after the optimization process.

[0036] Any embodiment of the first aspect can be adapted and implemented as an embodiment of the third aspect.

[0037] A fourth aspect of the invention is a computer-readable medium comprising computer instructions that, when executed by one or more processors, cause one or more processors to perform the methods of the third aspect and any embodiments thereof.

[0038] Other objects, features, embodiments, aspects, and advantages may be derived from the following detailed description, the appended claims, and the accompanying drawings. Attached Figure Description

[0039] The embodiments will now be described in more detail with reference to the accompanying drawings.

[0040] Figure 1 This is a schematic overview of an example blood processing device connected to a human individual.

[0041] Figure 2 This is a flowchart of an example control method according to an embodiment.

[0042] Figures 3A to 3C It is by the recipient Figure 2 A graph showing the ultrafiltration rate over time during an example treatment performed by a blood processing device controlled by a control method.

[0043] Figure 4 This is a flowchart illustrating a detailed example of a control method according to an embodiment. Detailed Implementation

[0044] Embodiments will now be described more fully below with reference to the accompanying drawings, in which some, but not all, embodiments are illustrated. In fact, the subject matter of this disclosure can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure may meet applicable legal requirements.

[0045] Furthermore, it should be understood that, where possible, any advantages, features, functions, devices, and / or optional aspects of any embodiment described and / or contemplated herein may include, and / or contemplated herein, any other embodiment, and / or vice versa. Furthermore, where possible, any term expressed in the singular form herein means that it also includes the plural form, and / or vice versa, unless otherwise expressly stated. As used herein, “at least one” should mean “one or more,” and these phrases are intended to be interchangeable. Thus, the terms “a” and / or “an” should mean “at least one” or “one or more,” even though the phrases “one or more” or “at least one” are used herein. As used herein, unless the context requires otherwise due to the language of expression or necessary meaning, the word “comprising” or variations such as “including” or “containing” are used in the meaning of inclusion, that is, indicating the presence of the stated feature but not excluding the presence or addition of other features in various embodiments. The term “and / or” includes any and all combinations of one or more of the associated listed items.

[0046] It should also be understood that although the terms first, second, etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of this disclosure, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

[0047] For the sake of brevity and / or clarity, well-known functions or structures may not be described in detail. Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0048] Throughout the text, similar figure labels indicate similar elements.

[0049] The embodiments relate to techniques for controlling ultrafiltration during extracorporeal blood processing. As used herein, “extracorporeal blood processing” refers to techniques for extracting blood from an individual, which may be human or animal, processing the blood outside the individual’s body to at least remove fluid from the blood, and returning the processed blood to the individual. The embodiments are applicable to any device operable to perform such extracorporeal blood processing, for example as part of extracorporeal kidney replacement therapy, including but not limited to hemodialysis (HD), hemofiltration (HF), and hemodiafiltration (HDF), or for supportive fluid removal between HD, HF, or HDF treatments, or as adjunctive therapy for patients with congestive heart failure (CHF).

[0050] Figure 1An embodiment of a device or system 1 for hemodialysis is illustrated. Device 1 includes an extracorporeal blood circuit 10 and a therapeutic fluid circuit, which are docked via a blood filtration unit 11. The blood filtration unit 11 defines a blood side and a therapeutic fluid side separated by a porous or semi-permeable membrane 11a. The filtration unit 11 can be any known dialyzer for hemodialysis, such as a spiral dialyzer, a parallel plate dialyzer, a hollow fiber dialyzer, etc. Typically, device 1 may include any number of blood filtration units that collectively define a “blood filtration apparatus.” The blood circuit 10 defines a blood extraction path or conduit 10a and a blood return path or conduit 10b, which are connected to the blood side of the filtration unit 11. The blood circuit 10 is fluidly connected to the blood system of individual 100 via any conventional device, such as a needle or tubing. One or more pumps 12 (one shown) are disposed in the blood circuit 10 and operable to draw blood from individual 100, pump the blood through the blood side of the filtration unit 11, and return the blood to individual 100. The blood pump 12 may be a peristaltic pump or any other suitable pump. The treatment fluid circuit includes a source 13 of fresh treatment fluid and a container or drain 14 for draining the fluid. The drained fluid includes used treatment fluid and fluid extracted from the blood (“ultrafiltrate”). The treatment fluid circuit includes an arrangement of fluid lines defining an inlet conduit 13a connected to an inlet on the treatment fluid side of the filtration unit 11, and an outlet conduit 14a connected to an outlet on the treatment fluid side of the filtration unit 11. A first pump 13b (“supply pump”) is disposed in the inlet conduit 13a to pump treatment fluid from the source 13, and a second pump 14b (“drain pump”) is disposed in the outlet conduit 14a to pump drained fluid toward the container 14. Pumps 14a and 14b may be peristaltic pumps or any other suitable type of pump.

[0051] The operation of pumps 12, 14a, and 14b is controlled by control signals C1, C2, and C3 generated by control system 30. Pumps 12, 14a, and 14b can be collectively designated as a "pumping device," which is controlled to achieve ultrafiltration of blood in filtration unit 11, and, in the example shown, dialysis treatment of blood. Specifically, the pumping device can be operated to establish a pressure gradient on membrane 11a to drive fluid through membrane 11a, as indicated by arrow 11b. It should be understood that... Figure 1 This is given merely as an example. For instance, in a device configured to perform ultrafiltration only, source 13, inlet conduit 13a, and supply pump 13b may be omitted.

[0052] In the illustrated embodiment, the control system 30 includes one or more processors 31 (one is shown) and a computer memory 32. A control program may be stored in the memory 32 and executed by the processor 31 to perform any of the methods, functions, or programs described herein. The control program, in conjunction with the processor 31 and the memory 32, defines the "logic circuitry" of the control system 30. The control program may be provided to the control system 30 in the form of a computer-readable medium, which may be a tangible (non-transitory) product (e.g., magnetic media, optical disc, read-only memory, flash memory, etc.) or a propagating signal. In an alternative embodiment, the control system 30 is configured with logic circuitry comprised of hardware components.

[0053] The control system 30 also includes an input interface 33a for connection to one or more sensor devices 20 (one shown) associated with the individual 100. The respective sensor devices 20 are configured to provide sensor data 102 representing one or more physiological parameters of the individual 100. As shown, the input interface 33a can also be configured to connect to one or more input devices 34 (one shown) that enable a user (“operator”) to provide input data. For example, the input device 34 may include a keyboard, keypad, computer mouse, control buttons, touchscreen, etc. Although in Figure 1 Although not shown, input interface 33a can also be configured to receive input signals from device 1, such as signals from various sensors, status signals, error signals, control signals, alarms, etc. Control system 30 also includes a first output interface 33b for providing control signals C1, C2, C3 to the pumping device, and a second output interface 33C for connecting to one or more output devices 35 (one shown), for example, for providing information to operators. For example, output devices 35 may include displays, indicator lights, alarm devices, speakers, printers, etc. Interfaces 33a, 33b, and 33c can be configured for wired or wireless connections.

[0054] It should be understood that, Figure 1 Only components relevant to the following description are shown. Other possible components of device 1 are also within the scope that can be determined by those skilled in the art, such as clamps, valves, sensors (flow rate, conductivity, pressure, air, blood, etc.), infusion chambers, pumps, heaters, filters, etc.

[0055] Device 1 is operated by control system 30 to perform a treatment course, which is a continuous period of time during which individual 100 is connected to device 1 and undergoes extracorporeal blood treatment to achieve a specific therapeutic purpose (e.g., to obtain a prescribed dose target and / or desired physiological state for individual 100). Before the treatment course begins, a caregiver or other operator may input control data for the treatment course, for example, by using input device 34. The control data may include the duration of the treatment course, the composition of the treatment fluid, the treatment fluid flow rate, the blood flow rate, the type of filtration unit 11, etc., and thresholds and / or restrictions to be applied during the treatment course. Conventionally, as described in the Background section, the control data also includes the total fluid (“total UF”) to be removed from the blood of individual 100 during the treatment course. However, in at least some embodiments described herein, inputting the total UF is not required.

[0056] Figure 2 This is a flowchart of a control method 200 that can be executed by the control system 30 according to an embodiment during a treatment. In step 201, the device 1 is operated to perform extracorporeal blood treatment while removing fluid from the blood at an ultrafiltration rate (hereinafter referred to as UFR). UFR represents the amount of fluid removed from the blood per unit time, given by a UFR setpoint. Step 202 can be performed continuously during method 200, or at least during the optimization process in step 203, in which fluid is removed from the blood from the blood at an ultrafiltration rate (hereinafter referred to as UFR). Figure 1 The associated sensor device 20 acquires sensor data 102. The optimization process in step 203 is configured to update the UFR setting value, which involves steps 203A-203C. In step 203A, the sensor data 102 is evaluated for detecting restrictive physiological states (hereinafter referred to as LPS). Step 203B is performed simultaneously with step 203A, operating device 1 to achieve different UFRs according to the test sequence of different UFRs. Whenever step 203A detects LPS, step 203B is stopped. At this time, step 203B therefore operates device 1 with the current UFR that caused LPS. In step 203C, the UFR setting value is updated based on the current UFR. According to an embodiment, step 203C may involve updating the UFR setting value to operate device 1 with the current UFR or with a predetermined relationship (above / below) to the current UFR. After step 203, the control method proceeds to step 201, where device 1 operates with the updated UFR setting value.

[0057] An optimization process 203 is performed to assess an individual’s current tolerance to ultrafiltration and identify appropriate UFR settings to prevent or reduce negative health effects on individual 100, where the occurrence of negative effects is represented by LPS.

[0058] It should be recognized that by optimizing process 203, control method 200 can reduce the risk of complications during dialysis while ensuring effective blood processing.

[0059] In some embodiments, LPS can be defined as representing an undesirable physiological state of individual 100 and / or as avoiding complications during dialysis for individual 100.

[0060] In some embodiments, optimization process 203 can be implemented to systematically find the current maximum UFR that maintains an individual's health. This can be achieved using a test sequence of UFRs, ordered by increasing magnitude. Thus, step 203B can involve progressively increasing the UFR, starting from the minimum UFR and ending when the current UFR causes an LPS. Consequently, optimization process 203 will consistently test the individual's response to progressively increasing UFRs, eliminating any hysteresis effects in the individual's response, such as the individual responding differently to increases and decreases in UFR by the same amount.

[0061] from Figure 2 As can be understood from the examples, the optimization process 203 can be performed more than once during the treatment course. Therefore, in some embodiments, the control method 200 performs a series of time-separated optimization processes 203 during the treatment course. Thus, the UFR will be intermittently adjusted for the physiological response of the individual 100. Since an individual's tolerance to the UFR can change as the treatment progresses, this will further reduce the risk of complications during dialysis.

[0062] In some embodiments, the test sequence is predetermined. In other embodiments, the test sequence is determined dynamically, for example, based on sensor data 102 and / or the time from the start of the treatment and / or one or more previous UFR settings generated by the optimization process 203. For example, the change in UFR between consecutive time steps in the test sequence may decrease after one or more time points during the treatment. Such time points may be, for example, specific times during the treatment, or time points identified when one or more UFR settings meet predetermined criteria, such as when the UFR settings fall to or exceed a specified threshold, or when consecutive UFR settings follow a specified trend.

[0063] In one embodiment, all test sequences in optimization process 203 start from the same minimum UFR (UFR). M Begin. This will ensure the consistency of operation of control method 200.

[0064] In some embodiments, when step 203B detects a UFR M During LPS, step 203C updates the UFR setting to a predetermined "UFR termination value". The UFR termination value results in a value lower than the UFR. MThe UFR (Ultrafiltration Rate), for example, is zero or close to zero. When LPS (Limited-Stage Precipitation) is detected at the beginning of the optimization process, this may indicate that the individual has reached or is close to their dry weight, and ultrafiltration should be terminated or at least significantly reduced for the remaining treatment. This embodiment enables fully automated control of ultrafiltration during treatment and eliminates the need for caregivers to assess and input total UF before treatment. These embodiments therefore potentially improve individual health and assist caregivers in fulfilling their caregiving tasks.

[0065] The foregoing embodiments are in Figures 3A to 3C Further examples are given below. Figures 3A to 3C It is used by blood processing device 1 during the treatment course Figure 2 The curve of UFR generated by the control method 200 in the middle.

[0066] exist Figure 3A In this treatment, the course begins at time Ts and ends at time Te. As mentioned above, Te can be input by the caregiver as part of the control data. At the start of treatment, method 200 controls device 1 to generate an initial ultrafiltration rate UFR0. In one example, UFR0 is a pre-stored value, which can be an individual-specific value or a value common to a group of individuals. In another example, UFR0 is determined by method 200 based on one or more previous treatments, such as based on the average UFR, median UFR, or maximum UFR obtained during previous treatments. In yet another example, UFR0 is input by the caregiver when preparing the treatment, for example, as part of the control data. In the example shown, method 200 performs four optimization procedures 203, which are separated by corresponding time intervals ΔT. Each optimization procedure evaluates a test sequence of progressively increasing UFRs through steps 203A-203B, such as... Figure 3A As shown. In the example shown, when step 203B detects the LPS of the current UFR in the test sequence, the UFR setting is updated to operate device 1 under that current UFR until subsequent optimization procedures begin or the treatment is terminated at time Te. In the example shown, throughout all optimization procedures 203, the test sequence starts from the same minimum ultrafiltration rate UFR. M Begin. As shown in the figure, different optimization processes 203 can produce different UFR setting values. Figure 3A During the final optimization process, due to the detection of UFR... M The LPS is reduced, so the UFR is set to zero, and ultrafiltration is automatically terminated.

[0067] Figure 3B An example of a test sequence for the UFR generated by optimization process 203 is shown. The test sequence begins with the UFR. MThe ultrafiltration rate is increased in steps with an amplitude of ΔUFR. In some embodiments, the step increase ΔUFR is given by a fixed value. Therefore, ultrafiltration can increase by a fixed absolute amount (as shown in the figure) or a fixed relative value, such as a percentage, between steps. However, it is conceivable to change the step increase ΔUFR in other ways during the optimization process 203. For example, the step increase ΔUFR can be reduced when the ultrafiltration rate exceeds a predetermined threshold. This would reduce the risk of the test sequence causing adverse effects on individual health due to the ultrafiltration rate.

[0068] exist Figure 3B In the example, solid dots represent the first time point at which the optimization process changes the UFR according to the test sequence, and hollow dots represent the second time point at which sensor data is acquired and evaluated for LPS detection. Therefore, the first and second time points are separated by a time interval Δt, which allows individual 100 to respond to the changed UFR. This "stabilization period" Δt will improve the effectiveness of method 200 in ensuring individual health and avoiding complications during dialysis. In one example, the stabilization period is in the range of 10–90 seconds, and the longest duration of the optimization process 203 is in the range of 1–10 minutes.

[0069] Figure 3C This is a graph showing another example of UFR changing over time during a treatment course performed according to method 200. In the example shown, the time interval of cycle 203 is optimized (see [link]). Figure 3A The time interval ΔT varies during the treatment course. Specifically, the time interval is smaller near the end of the treatment course. This can be advantageous because an individual's expected performance is an increase in sensitivity to ultrafiltration as excess fluid in their body is depleted. In some embodiments, the time interval ΔT is predefined and can therefore be predefined as varying over time, for example, related to the start time Ts. In some embodiments, the control method automatically initiates an optimization process 203 during the treatment course. Therefore, the time interval ΔT is not predetermined but dynamically determined by the control method 200. In some embodiments, the time interval ΔT is dynamically determined based on sensor data 102. For example, the control method 200 may initiate the optimization process 203 whenever sensor data 102 meets a predefined criterion. The predefined criterion can be LPS or any other physiological state of the individual. In some embodiments, the time interval ΔT is determined based on a UFR setpoint, i.e., the UFR setpoint determined by step 203C of the most recent optimization process 203. For example, if the UFR setpoint falls below a predefined threshold, the time interval ΔT may be reduced to a predefined value or reduced by a predefined absolute or relative amount. Control method 200 can also apply any combination of the foregoing embodiments to determine the time interval ΔT.

[0070] Figure 3CIt also shows when a UFR is detected M During LPS, the UFR is set as the UFR termination value, which typically occurs near the end of the treatment course. In the example shown, the method continues to initiate the optimization process 203 repeatedly after setting the UFR termination value to ensure that if the individual is found to require further ultrafiltration, the control method can increase the UFR again.

[0071] In some embodiments, when a UFR is detected in one or more optimization processes 203 M When LPS is reached, this control method can automatically terminate the treatment. Therefore, the treatment does not terminate at a predetermined time point Te related to the start time Ts, but rather when sensor data 102 determines that the individual has reached dry weight. For example, such an embodiment is applicable when the blood processing device 1 is configured to perform ultrafiltration only.

[0072] Figure 3C It also indicated the upper limit of UFR. LIM In some embodiments, the upper limit of UFR defines the maximum UFR that can be generated from the test sequence. It is also conceivable that whenever the generated UFR reaches a certain threshold... LIM When this occurs, control method 200 interrupts the treatment and / or generates an alarm or warning signal (e.g., in [location]). Figure 1 (On the output device 35 in the middle).

[0073] Back Figure 2Step 203A can detect a limiting physiological state (LPS) based on a single physiological parameter or a combination of physiological parameters of individual 100 as represented in sensor data 102. In the context of this disclosure, the term "physiological parameter" refers to any physiologically relevant quantity that can be monitored to determine one or more quantitative physiological levels associated with an individual. In some embodiments, LPS is detected based on at least one of blood volume, cardiac output, or vital signs. Blood volume is the total amount of blood in the circulatory system of individual 100. For example, changes in blood volume (also known as relative blood volume, RBV) can be measured online using commercially available devices. As used herein, blood volume is also intended to include hematocrit. Cardiac output is the volume of blood pumped by an individual's heart per unit time. Various techniques can be used to measure cardiac output, such as Doppler ultrasound, systolic and diastolic blood pressure analysis, impedance cardiography, electrical cardiometry, echocardiography, etc. Vital signs can include any physiological parameter routinely monitored by medical professionals and healthcare providers, such as skin (body) temperature, heart rate (pulse), respiratory rate (breathing rate), or blood pressure. Alternatively or additionally, vital signs can include one or more of the following: blood oxygen saturation level, skin color, urine output, mental status, capillary refill time, a measure of electrolyte balance in an individual, and a measure of acid-base balance in an individual.

[0074] Step 203B can detect LPS by performing a predefined evaluation function on the physiological parameters and evaluating the results relative to an evaluation criterion. The evaluation function can operate on the absolute value and / or relative change of the corresponding physiological parameter. In some embodiments, LPS can also be detected based on one or more operating parameters of the blood processing device, such as pressure measured in return path 10b and / or extraction path 10a. In a non-limiting example, the evaluation function is at least a function of blood volume and heart rate.

[0075] In some embodiments, LPS is predefined, for example, according to the evaluation criteria described above.

[0076] In some embodiments, the control method 200 further includes a calibration step performed during a calibration period. The calibration step may include obtaining corresponding initial values ​​for one or more physiological parameters from sensor data 102 and defining the LPS based on the corresponding initial values. For example, the calibration step may determine the aforementioned evaluation criteria based on the initial values.

[0077] In some embodiments, a calibration step is performed before or at the start of the treatment, such that the initial values ​​represent the physiological state of an individual unaffected by ultrafiltration.

[0078] Figure 4 This is a flowchart of control method 400, which is Figure 2 An example implementation of the control method 200. In step 401, the treatment duration is determined by a caregiver via input device 34. Figure 1 Input. Based on the treatment duration, control method 400 is able to determine the end time Te when the start time Ts is known. Although in Figure 4 Not shown, but step 401 may include the input of other control data by the caregiver, as described above. Steps 402-403 correspond to the calibration steps described above. In step 402, the corresponding initial values ​​of the physiological parameters are obtained from sensor data 102. In step 403, LPS is defined based on the initial values. For example, step 403 may include determining the assessment criteria described above. In step 404, the initial UFR (UFR0) and the minimum UFR (UFR) are determined. M For example, as described above. In step 405, the UFR setting value (UFR_SET) is set to UFR0. Step 406 operates the blood processing device to start the treatment, and step 407 controls the blood processing device to continuously achieve the ultrafiltration rate given by UFR_SET. Step 408 may check whether the treatment should be terminated, for example, in the event of an alarm condition, error detection, or if the end time Te has been reached. If the treatment should be terminated, step 408 proceeds to step 409. Otherwise, step 408 proceeds to step 410, which evaluates whether the optimization process should begin, for example, according to any embodiment for determining ΔT as described above. If the optimization process should not begin, ultrafiltration continues without change. Otherwise, step 410 continues to perform the optimization process, implemented by steps 411-418. In step 411, the UFR control parameter (TEST_UFR) is set to UFR0. M And modify one or more of the control signals C1-C3 of the pumping device to generate the corresponding UFR ( Figure 1 Step 412 ensures that the method remains stable during the steady-state period before proceeding to step 413. Figure 3B During the Δt period, the data from sensor data 102 ( Figure 1 Obtain the corresponding current values ​​of the physiological parameters. Step 414 evaluates the current values ​​for LPS detection, for example, by using the evaluation function described above. If no LPS is detected, step 415 proceeds to step 416, which checks whether TEST_UFR is at the upper limit of UFR (UFR). LIM If not, then step 416 proceeds to step 417, which increments TEST_UFR by ΔUFR. Figure 3BFor example, as described above, and proceed to step 412. If LPS is detected in step 415, the method proceeds to step 418, which updates UFR_SET based on TEST_UFR, and proceeds to step 407, which controls the blood processing device to continuously achieve the ultrafiltration rate given by the updated UFR_SET. Similarly, if step 416 determines that TEST_UFR is at the upper limit of UFR, the method proceeds to step 418.

[0079] While the invention has been described in conjunction with embodiments that are now considered to be the most practical and preferred, it should be understood that the invention is not limited to the disclosed embodiments, but rather is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

[0080] Furthermore, although the operations in the accompanying figures are described in a specific order, this should not be construed as requiring these operations to be performed in the specific order shown or sequentially, or requiring all the operations shown to be performed to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous.

Claims

1. A control system for an extracorporeal blood processing device (1), the control system comprising: A logic circuit (31) is configured to control the extracorporeal blood processing device (1) to draw blood from the individual (100) during the treatment, pump the blood through the blood filter device (11) and return it to the individual (100), and remove fluid from the blood in the blood filter device (11) according to a set value of the ultrafiltration rate. as well as An input interface (33a) is provided for sensor data (102), which represents one or more physiological parameters of the individual (100). The logic circuit (31) is further configured to intermittently perform an optimization process during the treatment to generate the set value based on the sensor data (102), the optimization process including: The sensor data (102) is evaluated for use in detecting the limiting physiological state (LPS) of the individual (100). The extracorporeal blood processing device (1) is sequentially controlled to achieve corresponding ultrafiltration rates in a sequence of different ultrafiltration rates until the assessment detects a limiting physiological state (LPS) for the current ultrafiltration rate, and The set value is updated based on the current ultrafiltration rate to continue the treatment after the optimization process; The evaluation includes obtaining sensor data (102) for the corresponding ultrafiltration rate, wherein the sensor data (102) for the corresponding ultrafiltration rate is obtained at a time interval (Δt) from the establishment of the corresponding ultrafiltration rate at the extracorporeal blood processing device (1). The sequences of different ultrafiltration rates are obtained by starting from the minimum value (UFR). M Start by increasing the range to sort; The control system is configured to perform at least two optimization processes during the treatment, wherein the minimum value (UFR) M The at least two optimization processes are equal.

2. The control system according to claim 1, wherein, The optimization process further includes, if the sensor data (102) indicates that the minimum value (UFR) is being optimized... M If the restricted physiological state (LPS) is detected, the setpoint will be updated to be lower than the minimum value (UFR). M The predetermined value.

3. The control system according to claim 2, wherein, The predetermined value corresponds to an ultrafiltration rate of zero.

4. The control system according to any one of claims 1 to 3, wherein, The limiting physiological state (LPS) is defined as an undesirable physiological state of the individual (100).

5. The control system according to any one of claims 1 to 3, wherein, The restrictive physiological state (LPS) is defined as the avoidance of complications during dialysis in the individual (100).

6. The control system according to claim 4, wherein, The restrictive physiological state (LPS) is defined as the avoidance of complications during dialysis in the individual (100).

7. The control system according to any one of claims 1 to 3, further configured to obtain corresponding initial values ​​of the one or more physiological parameters from sensor data during a calibration period, and to define the restrictive physiological state (LPS) based on the corresponding initial values.

8. The control system of claim 4, further configured to obtain corresponding initial values ​​of the one or more physiological parameters from sensor data during a calibration period, and to define the restrictive physiological state (LPS) based on the corresponding initial values.

9. The control system of claim 5, further configured to obtain corresponding initial values ​​of the one or more physiological parameters from sensor data during a calibration period, and to define the restrictive physiological state (LPS) based on the corresponding initial values.

10. The control system of claim 6, further configured to obtain corresponding initial values ​​of the one or more physiological parameters from sensor data during a calibration period, and to define the restrictive physiological state (LPS) based on the corresponding initial values.

11. The control system according to claim 7, wherein, The calibration time period is either before the treatment course or at the start of the treatment course.

12. The control system according to claim 8, wherein, The calibration time period is either before the treatment course or at the start of the treatment course.

13. The control system according to claim 9, wherein, The calibration time period is either before the treatment course or at the start of the treatment course.

14. The control system according to claim 10, wherein, The calibration time period is either before the treatment course or at the start of the treatment course.

15. The control system according to any one of claims 1 to 3, wherein, The one or more physiological parameters include at least one of vital signs, blood volume, or cardiac output.

16. The control system according to claim 15, wherein, The vital signs include one or more of the following: heart rate, blood pressure, blood oxygen saturation level, respiratory rate, skin temperature, skin color, urine output, mental status, capillary refill time, a measure of electrolyte balance in the individual (100), or a measure of acid-base balance in the individual (100).

17. The control system according to any one of claims 1 to 3, configured to autonomously initiate the optimization process during the treatment.

18. The control system of claim 4, configured to autonomously initiate the optimization process during the treatment.

19. The control system of claim 5, configured to autonomously initiate the optimization process during the treatment.

20. The control system of claim 7, configured to autonomously initiate the optimization process during the treatment.

21. The control system of claim 11, configured to autonomously initiate the optimization process during the treatment.

22. The control system of claim 15, configured to autonomously initiate the optimization process during the treatment.

23. The control system of claim 16, configured to autonomously initiate the optimization process during the treatment.

24. The control system according to any one of claims 1 to 3, wherein the optimization process is configured to begin execution based on any combination of the following conditions: a predetermined time interval (ΔT) to the previous optimization process, or based on the sensor data (102), or based on a set value generated by the previous optimization process.

25. The control system according to claim 4, which is configured to begin the optimization process based on the following conditions or any combination of the following conditions: according to a predetermined time interval (ΔT) to the previous optimization process, or according to the sensor data (102), or according to a set value generated by the previous optimization process.

26. The control system according to claim 5, which is configured to initiate the optimization process based on the following conditions or any combination of the following conditions: according to a predetermined time interval (ΔT) to the previous optimization process, or according to the sensor data (102), or according to a set value generated by the previous optimization process.

27. The control system according to claim 7, configured to initiate the optimization process based on any combination of the following conditions: a predetermined time interval (ΔT) to the previous optimization process, or based on the sensor data (102), or based on a set value generated by the previous optimization process.

28. The control system according to claim 11, configured to initiate the optimization process based on any combination of the following conditions: a predetermined time interval (ΔT) to the previous optimization process, or based on the sensor data (102), or based on a set value generated by the previous optimization process.

29. The control system according to claim 15, configured to initiate the optimization process based on any combination of the following conditions: a predetermined time interval (ΔT) to the previous optimization process, or based on the sensor data (102), or based on a set value generated by the previous optimization process.

30. The control system according to claim 16, configured to initiate the optimization process based on any combination of the following conditions: a predetermined time interval (ΔT) to the previous optimization process, or based on the sensor data (102), or based on a set value generated by the previous optimization process.

31. The control system according to claim 17, which is configured to begin the optimization process based on the following conditions or any combination of the following conditions: according to a predetermined time interval (ΔT) to the previous optimization process, or according to the sensor data (102), or according to a set value generated by the previous optimization process.

32. The control system according to claim 24, wherein, The predetermined time interval (ΔT) at the end of the treatment course is less than the predetermined time interval (ΔT) at the beginning of the treatment course.

33. The control system according to claim 25, wherein, The predetermined time interval (ΔT) at the end of the treatment course is less than the predetermined time interval (ΔT) at the beginning of the treatment course.

34. The control system according to claim 26, wherein, The predetermined time interval (ΔT) at the end of the treatment course is less than the predetermined time interval (ΔT) at the beginning of the treatment course.

35. The control system according to claim 27, wherein, The predetermined time interval (ΔT) at the end of the treatment course is less than the predetermined time interval (ΔT) at the beginning of the treatment course.

36. The control system according to claim 28, wherein, The predetermined time interval (ΔT) at the end of the treatment course is less than the predetermined time interval (ΔT) at the beginning of the treatment course.

37. The control system according to claim 29, wherein, The predetermined time interval (ΔT) at the end of the treatment course is less than the predetermined time interval (ΔT) at the beginning of the treatment course.

38. The control system according to claim 30, wherein, The predetermined time interval (ΔT) at the end of the treatment course is less than the predetermined time interval (ΔT) at the beginning of the treatment course.

39. The control system according to claim 31, wherein, The predetermined time interval (ΔT) at the end of the treatment course is less than the predetermined time interval (ΔT) at the beginning of the treatment course.

40. The control system according to any one of claims 1 to 3, configured to perform a series of time-separated optimization processes during the treatment.

41. The control system of claim 4, configured to perform a series of time-separated optimized processes during the treatment.

42. The control system of claim 5, configured to perform a series of time-separated optimization processes during the treatment.

43. The control system of claim 7, configured to perform a series of time-separated optimization processes during the treatment.

44. The control system of claim 11, configured to perform a series of time-separated optimization processes during the treatment.

45. The control system of claim 15, configured to perform a series of time-separated optimized processes during the treatment.

46. ​​The control system of claim 16, configured to perform a series of time-separated optimized processes during the treatment.

47. The control system of claim 17, configured to perform a series of time-separated optimized processes during the treatment.

48. The control system of claim 24, configured to perform a series of time-separated optimized processes during the treatment.

49. The control system of claim 32, configured to perform a series of time-separated optimized processes during the treatment.

50. The control system according to any one of claims 1 to 3, further configured to receive a user-defined duration value and set the duration of the treatment to the user-defined duration value.

51. An extracorporeal blood processing device, comprising: The pumping devices (12, 13b, 14b) are operable to draw blood from an individual (100), pump the blood through a blood filter device (11) and return it to the individual (100), while simultaneously removing fluid from the blood in the blood filter device (11) at an ultrafiltration rate. The control system according to any one of claims 1 to 50.

52. A computer-readable medium comprising computer instructions, which, when executed by one or more processors, cause the one or more processors to perform a method comprising the following steps: During the treatment, the extracorporeal blood processing device is controlled to draw blood from the individual through a blood filter device and pump the blood back to the individual, while removing fluid from the blood in the blood filter device according to a set value of ultrafiltration rate; To obtain sensor data representing one or more physiological parameters of an individual; as well as An optimization process is performed intermittently during the treatment to generate the set values ​​based on the sensor data; The optimization process includes: The sensor data is evaluated to detect an individual's limiting physiological state; The extracorporeal blood processing device is sequentially controlled to achieve corresponding ultrafiltration rates in a sequence of different ultrafiltration rates until the assessment detects a limiting physiological state for the current ultrafiltration rate; and The set value is updated based on the current ultrafiltration rate to continue the treatment after the optimization process; The evaluation includes obtaining sensor data (102) for the corresponding ultrafiltration rate, wherein the sensor data (102) for the corresponding ultrafiltration rate is obtained at a time interval (Δt) from the establishment of the corresponding ultrafiltration rate at the extracorporeal blood processing device (1). The sequences of different ultrafiltration rates are obtained by starting from the minimum value (UFR). M Start by increasing the range to sort; During the treatment course, at least two optimization processes are performed, wherein the minimum value (UFR) is... M The at least two optimization processes are equal.

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