MONITORING DEVICE AND METHOD FOR MONITORING AN EXTRACORPORAL BLOOD TREATMENT DEVICE

Description

[0001] The invention relates to a monitoring device for monitoring an extracorporeal blood treatment device, such as a dialysis machine, comprising an extracorporeal blood circuit with an arterial blood line and / or at least one venous blood line with a venous patient connection, and a dialysis fluid system comprising a dialysis fluid inlet and a dialysis fluid outlet. The invention further relates to a method for monitoring an extracorporeal blood treatment device according to the preamble of the dependent claim. Background of the invention

[0002] With external blood treatment devices, such as a dialysis machine, it is crucial to ensure flawless patient treatment. In particular, fluid flows must be monitored and precisely controlled. Valves are typically used to switch fluid flows or flow paths, whether it be blood or dialysis fluid. These can be, for example, pinch valves / clamps or valves directly integrated into a line. It is possible that a valve may not open or close correctly, and especially may not close completely. Reasons for this can include particles, calcification, or wear, which can impede the valve's mechanical closure or, for example, affect the pump.Particularly with valves, which are essential for accurate fluid flow balancing, flow deviations (ultrafiltration deviations) can occur. If a valve fails to close correctly during treatment, this can jeopardize the treatment and pose serious risks to the patient, in the worst case even leading to fatal consequences.

[0003] For example, in dialysis therapy using a dialysis machine, it is now standard practice to perform a so-called self-test of the machine before each treatment. This self-test verifies, among other things, that the valves close and operate securely and correctly. According to current technology, these self-tests are repeated periodically, for example, every one to two hours, to perform checks at discrete intervals. During this process, the therapy is briefly interrupted, usually for a few minutes, and then resumed. This self-test can therefore detect any internal defects in the dialysis machine. However, a disadvantage is that these periodic self-tests can only be performed a limited number of times and at specific intervals.There is a period of time between self-tests that is not monitored and during which, statistically speaking, no malfunction is likely to occur. This means that during this period, the therapy and the correct functioning of the blood treatment machine cannot be monitored. Furthermore, the self-tests interrupt therapy and prolong both the treatment and dialysis time.

[0004] In addition to self-tests, liquid and humidity sensors are also used in blood treatment devices to detect potential leaks. DE 10 2014 100260 A1, for example, discloses a system in which the humidity of air flowing into the housing is compared with the humidity of air flowing out of the housing. However, a disadvantage of this system is that the liquid sensors can only detect leaks in an open environment within the housing. If the fluid escapes in a closed volume within the housing, the humidity does not change, and the defect cannot be detected. Similarly, an internal leak occurring in a circuit (a special case of a closed volume), where, for example, a valve does not close properly, cannot be detected by such a system.

[0005] In addition, it is possible to monitor an electrical current or voltage applied to a valve to analyze whether the valve is switching correctly. However, such monitoring is limited to detecting only an electrical fault and cannot determine whether a leak is caused by, for example, a mechanical blockage or wear of the valve.

[0006] Other defects that can occur in a blood treatment machine, and especially in a dialysis machine, include, for example, a worn pump, misadjusted throttles, clogged filters or wear and tear, as well as product defects in technical components.

[0007] German patent DE 10 2009 024 864 A1 discloses a method and a device for monitoring a fluid system of an extracorporeal blood treatment device. The pressure in a vent line branching off from a venous drip chamber is measured and evaluated, with a valve being alternately at least partially opened and closed. The measured pressure signal is therefore subject to pressure fluctuations when no fault is present. In addition to the blood treatment device, a pressure in a supply line is measured, and a trigger for generating a pressure pulse is used. Furthermore, it is difficult to cyclically open and close a valve on one side of the dialysis fluid to generate a pressure change as a trigger signal. A valve that does not close correctly is difficult to detect.

[0008] WO 2007 / 006348 A1 and DE 10 2009 060 668 A1 disclose a drug delivery system for liquid medications and a monitoring device that monitors the flow rate of pumped blood. The latter document requires the use of centrifugal pumps, which limits the design of a dialysis machine. These systems are also difficult to adapt to the dialysis fluid side in order to determine if a defect exists there.

[0009] German patent DE 10 2015 016 271 A1 discloses a system and a method for detecting an operating state or treatment progress of a blood treatment. During a blood treatment, an operating parameter of a blood treatment machine is continuously monitored, and its time-dependent course of a measurement signal is recorded. If the treatment progress deviates from an ideal or complication-free treatment progress, a user input is required.

[0010] DE 10 2014 015 048 A1 discloses a method for event-driven limit setting within the framework of monitoring a dialysis machine. In this method, state variables are stored in a state vector. Measurement signal vectors corresponding to the state vector are compared with reference state vectors, and a medical device is controlled and monitored using target limit settings.

[0011] US patent 2009 / 0292236 A1 discloses a method for monitoring an extracorporeal blood circulation and a device for detecting a deviation between a predetermined target course and the actual course. Summary of the invention

[0012] The objects and objectives of the invention are to eliminate or at least mitigate the disadvantages of the prior art and, in particular, to provide a monitoring device and a method that can detect defects with minimal additional effort at various points in the blood treatment device with high reliability, ensure safe, reliable, cost-effective, and simple monitoring of an extracorporeal blood treatment device, shorten the duration of dialysis therapy, and also allow for fine-tuning of monitoring parameters. Furthermore, continuous monitoring during treatment should be possible.

[0013] The tasks and objectives of a monitoring device of the generic type are solved according to the invention by the subject matter of the independent claims. The invention is therefore based on the understanding that the blood treatment device, without any further necessary modifications to the device, continuously provides sufficient measured values / parameters that are sufficiently informative about the functional reliability of the blood treatment device as a whole or of selected components or sections.

[0014] The monitoring device according to claim 1 is configured / adapted to select and capture (at least) one measured value / measurement signal / status measurement / parameter occurring and detected by and during the operation of the extracorporeal blood treatment device, which is suitable for monitoring the blood treatment device with sufficient significance. In other words, the monitoring device is connected to, or can be coupled to, at least one sensor / detector of the blood treatment device that detects measured values / status parameters of the extracorporeal blood treatment device.

[0015] The monitoring device is accordingly adapted to capture a measurement value from the extracorporeal blood treatment device, which is recorded for the operation of the extracorporeal blood treatment device by at least one sensor of the blood treatment device. No additional components, such as a trigger to generate periodic pressure pulses, are required; instead, it utilizes existing measurement values ​​that are recorded during the operation of the blood treatment device or during treatment. In particular, only "core measurement values" are used. "Core measurement values" in this case means that these measurement values ​​must be obtained by the blood treatment device anyway for proper treatment.The system utilizes existing data from the blood treatment device and its sensors as much as possible, employing appropriate algorithms and evaluation methods to detect malfunctions or defects in the device or in one or more selected components. The monitoring system's reliability is enhanced by having different target profiles stored for various measured values. Correlations between the measured values ​​can also be considered. By evaluating key measured values, the monitoring system can detect defects at various points within the blood treatment device. The near-continuous acquisition of measured values ​​throughout the treatment period also allows for the detection of a valve with a delay. For example, if a valve fails to close correctly, the pressure profiles will change characteristically.This is particularly noticeable with valves that open and close cyclically. The monitoring device or its memory can preferably also incorporate pattern recognition methods for comparison and determination.

[0016] Accordingly, the monitoring device according to claim 1 can, using recorded measured values ​​such as pressure, temperature, flow rate, conductivity, and / or membrane position, infer one or possibly several defects during an ongoing treatment or during operation of the blood treatment device without interrupting the treatment. By storing a target profile in the monitoring device's memory, a defined (ideal) setting can be saved, ensuring that the treatment proceeds correctly. With the help of the monitoring device, a defect in the blood treatment device can be inferred continuously, safely, and reliably, and in particular, internal leaks can be efficiently detected. The target profiles can be defined, for example, through experimental measurements beforehand or via a computer-aided, simulated profile.

[0017] According to the invention, the monitoring device's memory stores (in addition to the target curve of the measured value) one or more error curves of the measured value. The monitoring device determines that a defect exists if, at least in certain sections, the actual curve of the recorded measured value deviates from the target curve of the stored measured value beyond a defined tolerance, and if, at least in certain sections, the actual curve of the recorded measured value corresponds to the stored error curve of the measured value within a defined second tolerance. In particular, characteristic error curves of, for example, a valve that does not close correctly, a worn pump with reduced pumping capacity, a misadjusted throttle with corresponding consequences, or a clogged filter can be stored in the memory as a reference.These error patterns can be determined experimentally or theoretically in advance. Consequently, if only one or a limited number of errors occur, a direct comparison of the actual behavior with the corresponding error pattern can identify the cause of the error, such as a kinked tube or a blockage, thus facilitating traceability and repair. In particular, the monitoring device can instruct the blood treatment device to perform a comprehensive self-test and analyze the defect after a fault has been detected.

[0018] Advantageous embodiments are claimed in the dependent claims and are explained below.

[0019] In a preferred embodiment, the monitoring device can acquire the measured values ​​in real time during operation of the extracorporeal blood treatment device without any time delay. This means that only a physically occurring signal propagation time with associated signal processing occurs, but no further (intentional and avoidable) delay. This allows for the creation of a kind of "online" or real-time monitoring device, enabling a user or operating personnel to intervene immediately in the event of a defect or malfunction detected by the monitoring device in either the blood treatment device or a component.The monitoring device is capable of detecting the defect immediately, i.e., without delay, and initiating necessary measures, such as interrupting treatment by closing a valve or other appropriate actions, thus eliminating or at least minimizing any risk to the patient. The monitoring device can therefore detect a defect or malfunction of a component of the blood treatment device, and thus the blood treatment device itself, "online," i.e., during treatment, without interrupting the therapy and without additional tests, such as a self-test, which is only suitable for identifying specific defects. "Online" here defines a procedure that can be carried out during therapy without interrupting the therapy and without having to perform dedicated procedures solely for detecting a fault.This means that an "online" method allows for the detection of a defect solely based on the signal patterns caused by the therapy. The term "defect" also includes any malfunction.

[0020] In particular, the monitoring device has an interface that allows it to be connected, or at least connectable, to the extracorporeal blood treatment device, at least via data transmission. This interface can be wireless, for example, in the form of Bluetooth® or WLAN. If the monitoring device detects a defect in the blood treatment device, it can send a corresponding control command and / or error code to the blood treatment device via the interface, enabling the latter to initiate appropriate measures to protect the patient.

[0021] In a preferred embodiment, the monitoring device can acquire a measured value of the voltage, current, and / or rotational speed of a pump located in the extracorporeal blood treatment device, in the extracorporeal blood circuit for pumping blood, and / or in the dialysis fluid system for pumping dialysis fluid. This allows for the determination of whether a defect exists, as, for example, the pump's rotational speed can indicate whether a downstream or upstream valve is correctly (completely) closed or, contrary to the circuit's design, is allowing flow. Additionally or alternatively, the monitoring device can acquire a measured value of pressure, temperature, flow rate, conductivity, and / or diaphragm position.

[0022] In a preferred embodiment, the monitoring device can, after a start signal, detect the actual trend of the measured value(s) for a predetermined detection time and set this detected actual trend as the target trend of the corresponding measured value stored in the monitoring device's memory. In this way, an actual trend for each relevant measured value can be recorded individually for each extracorporeal blood treatment device, for example, after verifying that the blood treatment device is functioning correctly (a kind of verified, correct trend), which is then subsequently stored in the memory as the target trend of the corresponding measured value. The monitoring device can be connected to different blood treatment devices and calibrated accordingly via the recording.A detailed template and definition of a target curve for each relevant measurement value during the production of the blood treatment device (for each individual unit, with fine calibration) is not necessary. Furthermore, the target curve can be recorded in real time after verifying the correct functioning of the blood treatment machine, thus significantly reducing the impact of external influences, which naturally occur during production and operation, on the recorded measurements.

[0023] Preferably, the criteria for the defined first and / or second tolerance can be a slope and / or an absolute measurement deviation and / or a standard deviation between the actual and target curves and / or between the actual and error curves of the measured value. A theoretically or experimentally defined target or error curve will not, in reality, correspond 100% to the actual curve. Rather, the actual curve will move within a certain range, or, more figuratively speaking, within a certain corridor, which represents the confidence interval around the target or error curve. If the actual curve lies within the confidence interval around the target curve, the monitoring device determines that no defect is present. The definition and configuration of this confidence interval and its defined limits are achieved through the criteria mentioned above.In particular, all three criteria—namely, a slope, an absolute measurement deviation, or a standard deviation—can be required, meaning that a deviation of only one criterion is sufficient. Similarly, it can be required that a false alarm is triggered only if the slope, the absolute measurement deviation, and the standard deviation of the actual curve deviate from the target curve or the error curve. This prevents false alarms, as all three criteria must be met. Preferably, an approximation error or a measurement deviation can be used as an alternative or additional measure.

[0024] Additionally or alternatively, in a preferred variant, a minimum and / or maximum value of the actual measured value over a defined period can be used as a criterion for the defined first and / or second tolerance, compared to the stored target value and / or the stored error value. Here, a kind of upper and / or lower limit can be imposed on the target value, within which the actual value should fall, in a stepwise manner. This time period could, for example, be a balance chamber cycle or a flushing cycle. Preferably, an (absolute) difference between the first and last measured values ​​within a defined period can also be used as a criterion.

[0025] In a preferred embodiment, which may be claimed independently, the monitoring device can acquire and record at least two (i.e., more than two) measured values. The monitoring device can consider the behavior and / or correlation of these measured values ​​when comparing their trends and determining whether a defect is present. Thus, the monitoring device can not only consider the measured values ​​individually and separately, but also, when evaluating at least two measured values, take into account any correlation between them and use this correlation to determine whether a defect is present. For example, pressure and temperature can be recorded. If the pressure and temperature exhibit a corresponding trend that correlates with each other, the monitoring device can determine whether a defect is present.

[0026] According to a further aspect of the invention, when a defect is detected and determined by the monitoring device, an acoustic, visual, and / or tactile (alarm) signal can be output by a unit. The malfunction can thus be communicated acoustically, visually, and tactilely to an operator of the blood treatment device, and intervention in the control of the blood treatment device can be initiated. For example, the alarm signal could inform the operator and the patient, and the operator could stop a blood pump and close a venous tubing clamp, or, if this has already occurred automatically, be informed that a defect has occurred.

[0027] The object and objectives of the invention are also achieved by a method according to claim 11. Similar to the monitoring device, this method compares the actual trend of the recorded measured value with the corresponding target trend and the error trend of the measured value, and accordingly determines whether a defect exists. With regard to the method, the invention, like that of the monitoring device, is based on the understanding that the blood treatment device, without any further necessary modifications, continuously provides a sufficient number of measured values / parameters that are sufficiently informative about the functional reliability of the blood treatment device as a whole or of selected components or sections.

[0028] In a preferred embodiment / variant of the method, the comparison step can comprise the following steps: calculating the standard deviation between the actual measured value and the target value and / or the error curve of the measured value; and comparing the calculated standard deviation with a stored target standard deviation. The criterion of a standard deviation or sample deviation for the first and / or second tolerance is a good choice for the implemented function, since the standard deviation allows for a certain degree of error tolerance over time, and a single value, namely the target standard deviation, is sufficient to determine whether the curves correspond. Here, a corresponding target standard deviation can be defined for the entire duration of a treatment or for specific (time) intervals. Brief description of the characters

[0029] The invention is explained in more detail below with the aid of figures and preferred examples. These show: Fig. 1 Figure 1 shows a highly simplified schematic view of a first example of a monitoring device with an extracorporeal blood treatment device, wherein this blood treatment device is not according to the invention. Fig. 2 a graph of a comparison of the monitoring device in which an actual curve, within a tolerance, is compared with a target curve, Fig. 3 a graph of a comparison of the monitoring device where the actual trend does not correspond to the target trend, Fig. 4 a graph of a comparison of the monitoring device in which an actual curve, within a tolerance, is compared with an error curve, Fig. 5 a graph of a comparison of the monitoring device where the actual curve does not correspond to the error curve, Fig. 6a graph with an exemplary comparison of a target curve and an error curve, and Fig. 7 A flowchart of a method for monitoring an extracorporeal blood treatment device. However, this method is not according to the invention.

[0030] The figures are schematic and serve only to illustrate the invention. Identical elements are marked with the same reference symbols. The features of the different examples are interchangeable. Detailed description of preferred embodiments

[0031] Figure 1 Figure 1 shows a preferred embodiment of a monitoring device 1 according to the invention. The monitoring device 1 serves to monitor an extracorporeal blood treatment device, in particular a hemo(dia)filtration device, in the form of a dialysis machine 2 for blood purification or filtration of blood. Figure 1The figure shows only the essential components of the blood treatment device in a schematic representation. The dialysis machine 2 has a dialyzer 4 or filter, which is divided by a semipermeable membrane 6 into a first chamber (blood chamber) 8 and a second chamber (dialysis fluid chamber) 10.

[0032] From a patient (not shown), an arterial blood line 12 in the form of a flexible, elastic tube leads from an arterial puncture cannula 13 (as the patient's arterial connection) to the first chamber 8 of the dialyzer 4. The direction of blood flow is indicated by an arrow pointing Figure 1The first chamber 8 is marked. A venous blood line 14 leads back to the patient from the outlet of the first chamber 8. The venous blood line 14, in the form of a flexible, elastic tube, is connected to a shunt or fistula on the patient using a venous puncture cannula 16. A peristaltic blood pump 18 is arranged in the arterial blood line 12 to pump the patient's blood. A bubble catcher (not shown) is also arranged in the venous blood chamber to remove air from the pumped blood before it is returned.

[0033] A dialysis fluid system 20 of the blood treatment device comprises a dialysis fluid source 22 to which a dialysis fluid supply line 24 is connected, leading into the second chamber 10 of the dialyzer 4. A dialysis fluid outlet 26 extends from the outlet of the second chamber 10, leading to a dialysis fluid drain 28. The dialysis fluid is pumped in the dialysis fluid system 20 by at least one dialysis fluid pump 30, such as a peristaltic pump or a centrifugal pump.

[0034] The dialysis machine 2 is controlled by an electronic control unit (ECU) 32. The ECU 32 controls, among other things, the blood pump 18 and the dialysis fluid pump 30, and also acquires measured values ​​from the blood treatment device. For this purpose, a sensor 34 is attached to each of the lines: the arterial blood line 12, the venous blood line 14, the dialysis fluid supply line 24, and the dialysis fluid outlet 26. The sensor 34 is always the same and measures the pressure, temperature, and flow rate of the respective line 12, 14, 24, and 26, respectively. Of course, different sensors with different functionalities can also be arranged, depending on the application. For example, only one sensor 34 could be attached to the venous blood line 14, measuring only the pressure.The only important thing is that the dialysis machine 2 has at least one sensor 34 to record measured values ​​for the ECU 32.

[0035] The sensors 34 transmit the data / information of the measurement signals or measured values ​​to the ECU 32, either wired or wirelessly. To actuate or control the blood-side circulation, the dialysis machine 2 has, among other things, a valve in the form of an electromagnetic hose clamp 36, which seals the venous blood line 14 by pinching, thus stopping the blood flow. When the venous hose clamp is closed, the fluid flow in the extracorporeal blood circulation is interrupted. On the side of the dialysis fluid system 20, the dialysis machine 2 also has a valve 37, which can control and also stop the flow through the dialysis fluid supply line 24. The dialysis machine 2 also has an interface 38, with which the dialysis machine 2 is connected to the monitoring device 1 for data transmission. For the sake of understanding and illustration, Figure 1The data flow of the connection is split into data output and data input. For example, if valve 37 does not close correctly, this can be detected by monitoring device 1.

[0036] The extracorporeal blood treatment device 2 also includes balance chambers for the volumetric balancing of fluids. Each balance chamber is divided into two compartments by an elastic membrane. Depending on the amount of fluid in each compartment, the membrane is deflected towards one compartment or the other. A position sensor allows the extracorporeal blood treatment device 2 to measure the membrane's position. Additionally, the extracorporeal blood treatment device 2 incorporates conductivity cells to dose dialysis concentrates at the correct concentration into the dialysis fluid. During operation, the corresponding conductivity signal profiles are recorded.

[0037] The dialysis machine 2 transmits the data of the recorded measured values, e.g., pressure, temperature, and flow rate of all four lines, via interface 38 in real time, i.e., without any time delay. This means that only a physically occurring signal propagation time with associated signal processing occurs, but no further (intentional and avoidable) delay. The data is transmitted wirelessly or, alternatively or additionally, via cable to a receiving unit 40 (as part of an interface on the monitoring device side) of the monitoring device 1. The receiving unit 40 forwards the recorded and accessed measured values ​​to a central control unit 42, which selects and processes the measured values. The central control unit 42 has a recording memory 44 in which an actual trend 46 is recorded, and a memory 48 in which target trends 50 of the respective measured values ​​are stored.In addition to the target profiles 50 of the respective measured values, error profiles 52 for the corresponding measured values ​​are also stored in memory 48. The acquisition memory 44 and the memory 48 can also be physically configured in a single, shared memory element.

[0038] A comparison unit 54 of the monitoring device 1 compares the actual curve 46 with the target curve 50 for each measured value, as well as the actual curve 46 with the error curve(s) 52. If the actual curve 46 deviates from the target curve 50 by a defined tolerance 56, a determination unit 58 determines that a defect in the dialysis machine 2 exists. In other words, the determination unit 58 determines, based on the result of the comparison performed by the comparison unit 54, whether a defect exists. This is the case if the actual curve 46 deviates from the target curve 50 by a defined tolerance 56. The determination unit 58 also determines that a defect exists if the actual curve 46 corresponds to or agrees with an error curve 52 within a defined tolerance 56. The comparison of the respective actual curves with the corresponding target curves 52 and error curves 52 is performed by the device 1.The error patterns of the comparison unit 54 and the determination by the determination unit 58 as to whether a defect is present are described in the description of the . Figures 2 and 3 Explained in detail.

[0039] If a defect is detected, an audible, visual, and / or tactile alarm signal is emitted via an output unit in the form of an alarm transmitter 60. Simultaneously, a control command is sent via the alarm transmitter 60 to the interface 38 of the dialysis machine 2 via a transmitter unit 41. Alternatively or additionally, the monitoring device 1 can also send only an error code to the ECU 32 of the dialysis machine 2 via the transmitter unit 41. Based on the error code, the dialysis machine 2 can then independently determine which measures should be taken. Thus, the dialysis machine 2 continues to operate "autonomously," and control remains solely with the dialysis machine 2.The control command can preferably instruct the ECU 32 of the dialysis machine 2 to stop the blood pump 18 and the dialysis fluid pump 30, and to completely close the electromagnetic hose clamp 36 and the valve 37. Furthermore, if, for example, the valve 37 does not close completely, even though it should be closed (e.g., for a change of the dialysis fluid), the sensors 34 and ultimately the monitoring device can determine that a defect has occurred. The hose clamp 36 is then immediately closed. Thus, any risk to the patient in the event of a detected defect is directly and immediately prevented.

[0040] Figure 2To illustrate the precise functionality of the comparison and determination processes using the comparison unit 54 and the determination unit 58, respectively, a graph with exemplary curves is shown. The abscissa represents time (for the curve), and the ordinate represents the amplitude or absolute value of the measured value of the curves. The target curve 50, in the form of a sine wave (for illustrative purposes), is stored in the memory 48 of the monitoring device 1. An absolute measurement deviation with a constant deviation value 62, which applies in both the negative and positive directions (of the amplitude), is chosen as the criterion for the tolerance 56. Thus, a kind of corridor / tube / band is formed around the target curve 50, representing the defined tolerance 56 or confidence interval.

[0041] The actual trend 46 is also in Figure 2The actual trend 46 is recorded from time T0 (for example, the start of recording the measured values ​​or the start of treatment) and is recorded up to the present time TA and stored in the acquisition memory 44. As shown from Fig. 2 As can be seen, the actual curve 46 lies within the tolerance 56 of the target curve 50 for the corresponding measured value. Therefore, the monitoring device 1 does not determine that a defect exists, or in other words, the monitoring device 1 determines that there is currently no defect.

[0042] It should be noted at this point that the in Figure 2 The graph shown applies to exactly one measured value (from, of course, one line). For example, in Fig. 2A current trend 46 of the pressure of the venous blood line 14 is shown. In the same way, a measured value such as the temperature of the dialysis fluid supply line 24 can of course also be used.

[0043] Figure 3 The diagram shows an actual curve 46, in which the actual curve 46 remains constant and also, in sections, outside the tolerance 56 of the target curve 50. Here, the monitoring device 1 determines at a first time point T1, when the actual curve 46 leaves the tolerance 56, or, if a certain period of time for the actual curve 46 to remain outside the tolerance 56 were allowed, at the latest at a second time point T2, that a defect in the dialysis machine 2 has occurred. The treatment is stopped, the pumps 18, 30 are stopped, and the hose clamp 36 is closed.

[0044] Figure 4 shows, similar to the comparison from Fig. 2, a comparison of the actual curve 46 with the error curve 52. The monitoring device 1 compares not only the target curve 50 but also the error curve 52 using the same procedure, but with the difference that if the actual curve 46 lies within the tolerance 56 of the error curve 52, the determination unit 58 or the monitoring device 1 now determines that a defect actually exists.

[0045] Figure 5 shows, similar to the comparison from Fig. 3A comparison of the actual curve 46 with the fault curve 52 is performed, where the actual curve 46 does not follow the fault curve 52. It is determined that (except for the areas around times T1 and T2) the actual curve 46 does not correspond to the fault curve 52, and therefore no defect is present. The passages of the actual curve 46 within the corridor / tube area (tolerance 56) around the fault curve 52 must, of course, be evaluated, and it must be defined that these deviations lie outside the tolerance.

[0046] It is important that for each individual measured value, such as temperature, a separate target curve 50 or one or more error curves 52 for precisely this measured value and precisely this line are stored in memory 48. If necessary, multiple target curves 50 can even be stored for each individual measured value, for example, for different types of therapy or modes of the extracorporeal blood treatment device.

[0047] Figure 6 shows a graph, where in the left part of the Figure 6 For illustration, an exemplary pressure curve (PDA - pressure sensor, dialysis fluid outlet) during normal therapy according to a target curve of 50 is shown, whereas in the right part of the Figure 6The measured value shows a pressure curve following an error curve 52, indicating a defect and disrupting patient therapy. Error curve 52 represents therapy with a defective balance chamber valve, where the valve does not close correctly. Consequently, the graph, or pressure curve, has a sawtooth profile.

[0048] Figure 7 shows a method 100 of a variant for monitoring an extracorporeal blood treatment device, such as a dialysis machine 2 (see Fig. 1), with an extracorporeal blood circuit comprising an arterial blood line 12 with an arterial patient port 13 and / or at least one venous blood line 14 with a venous patient port 16, and a dialysis fluid system 20, wherein a measured value is recorded by the monitoring device during operation of the extracorporeal blood treatment device. After the start of the procedure 100, a selection is performed in step 101 and a continuous recording and recording of a measured value is performed in step 102. The procedure shown is described for a single measured value, for example, the pressure of the venous blood line 14. Of course, not only one measured value, but also several measured values, for example, pressure, temperature, and flow rate, can be recorded from different sections of the lines of the blood treatment device. The procedure 100 is then carried out for each individual measured value.

[0049] After step 102, the process 100 proceeds to step 104, where the recorded measured value is added to the existing actual trend. This supplements the actual trend recorded up to that point with the current measured value, so that the updated actual trend is continuously and in real time available to the process 100. After step 104, in the subsequent block 106, the actual trend is compared with a target trend and the actual trend with an error trend. Specifically, the process proceeds to step 108, where a standard deviation is calculated between the actual trend and the target trend. In particular, this step calculates a standard deviation of the individual continuously recorded measured values ​​from time T0 to time TA (see also Figs. 2 and 3). Instead of time T0, it is also conceivable to choose a later time in order to analyze only a specific past period and to calculate the standard deviation between the actual trend and the target trend within that period.

[0050] As a result of calculating the standard deviation in step 108, an absolute value is obtained, which is compared in condition 110 with a stored target value or a stored target standard deviation. If the standard deviation value is lower than the target standard deviation (No), and thus the actual trend is within the tolerance of the target trend, the procedure proceeds to step 112, "Calculating the Standard Deviation - Error Trend." However, if the calculated standard deviation in condition 110 is greater than the target standard deviation (Yes), the actual trend is outside the tolerance of the target trend, and the procedure proceeds to block 114, "Defect Determination."

[0051] In step 112, "Calculating the Standard Deviation of the Error History," essentially the same as in step 108, the standard deviation between the actual history and a predefined error history is calculated. Here too, instead of the time interval T0 to TA, any time interval T1 or T2 to TA can be used.

[0052] In a subsequent condition 116, it is checked whether the calculated standard deviation is less than a target standard deviation. This target standard deviation of condition 116 may differ from the target standard deviation of step 108, depending on the definition. Both target standard deviations are required to ensure a centrally controlled variable. If the calculated standard deviation is less than the target standard deviation (Yes), the comparison shows that the actual curve lies within the tolerance of the error curve. The procedure then proceeds, as with condition 110, to the defect determination block 114. However, if the standard deviation is greater than the target standard deviation, the procedure continues to condition 118, which checks whether the processing is complete. It should be noted here that, of course, multiple error curves 52 can be stored for exactly one measured value.Should this be the case, step 112 and condition 116 will be repeated for each additional error history, so that only after checking all error histories of the measured value does the procedure continue to condition 118 or the defect determination block 114.

[0053] Condition 118 checks the treatment status. If the treatment is not yet complete (No), another loop is added to the procedure by directing it to step 102, the sampling step. If, however, the patient's treatment is complete (No), there is no need to monitor the blood treatment device, and the procedure ends.

[0054] The Defect Determination block 114 comprises the Determine that a defect exists step 120, the Intervention in the Control of the Blood Treatment Device step 122, and the Alarm Output step 124. In the Intervention in the Control of the Blood Treatment Device step 122, the procedure stops the blood treatment device, the pumps are stopped, and, in particular, a valve or hose clamp of the venous blood line and a valve of the dialysis fluid supply line 24 are closed, for example, via a control command sent to the blood treatment device. The Alarm Output step 124 can be visual, for example, on a display of the blood treatment device, a flashing light, an audible alarm in the form of a beep, or a tactile alarm such as a vibration. The procedure stops after the Defect Determination block 114. Reference symbol list

[0055] 1 Monitoring device 2 Dialysis machine 4 Dialyzer 6 Semipermeable membrane 8 First chamber 10 Second chamber 12 Arterial blood line 13 Puncture cannula for arterial patient connection 14 Venous blood line 16 Puncture cannula for venous patient connection 18 Blood pump 20 Dialysis fluid system 22 Dialysis fluid source 24 Dialysis fluid inlet 26 Dialysis fluid outlet 28 Dialysis fluid drain 30 Dialysis fluid pump 32 Electronic control unit / ECU 34 Sensor 36 Hose clamp 37 Valve 38 Interface 40 Receiver unit 41 Transmitter unit 42 Central control unit 44 Data acquisition memory 46 Actual history 48 Memory 50 Target history 52 Error history 54 Comparison unit 56 Tolerance 58Determination unit 60Alarm transmitter 62Deviation value T0Start time T1First time T2Second time TACurrent time 100 Procedure 101 Step Select 102 Step Extract 104 Step Add Measured Value 106 Block Compare 108 Step Calculate Standard Deviation 110 Comparison Condition 112 Step Calculate Standard Deviation 114 Block Defect Determination 116 Comparison Condition 118 Condition Treatment Completion 120 Step Determine Defect 122 Step Intervention in Control 124 Step Alarm Output

Claims

1. A monitoring device (1) for monitoring an extracorporeal blood treatment device (2), such as a dialysis machine, comprising an extracorporeal blood circuit which has an arterial blood line (12) with an arterial patient port (13) and / or at least one venous blood line (14) with a venous patient port (16), and a dialysis fluid system (20) which has a dialysis fluid supply line (24) and a dialysis fluid drain line (26), characterized in that one or more error courses (52) of a measured value are stored in a memory (48) of the monitoring device (1) in addition to a target course (50) of the measured value, and the monitoring device (1) is configured to select and sense the measured value occurring and detected by and during operation of the extracorporeal blood treatment device (2) and which is suitable for monitoring the blood treatment device (2), to compare a time-related actual course (46) of the detected measured value with the target course (50) of the associated measured value stored in the memory (48) of the monitoring device (1) and with at least one of the one or more error courses (42) of the associated measured value, and to determine that there is a defect if, at least in sections, the actual course (46) of the detected measured value deviates from the target course (50) of the stored measured value by more than a first defined tolerance (56), and if, at least in sections, the actual course (46) of the detected measured value coincides with the stored error course (52) of the measured value within a second defined tolerance (56).

2. The monitoring device (1) according to claim 1, characterized in that the monitoring device (1) detects the measured values during operation of the extracorporeal blood treatment device (2) in real time without any time delay.

3. The monitoring device (1) according to any of the preceding claims, characterized in that the monitoring device (1) senses a voltage and / or a current and / or a rotational speed of a pump (18; 30) arranged in the extracorporeal blood treatment device (2) in the extracorporeal blood circuit for conveying blood and / or in the dialysis fluid system (20) for conveying dialysis fluid, as the detected measured value.

4. The monitoring device (1) according to any of the preceding claims, characterized in that the monitoring device (1) senses a pressure and / or a temperature and / or a flow and / or a conductivity and / or a membrane position as the detected measured value.

5. The monitoring device (1) according to any of the preceding claims, characterized in that the monitoring device (1) detects the actual course (46) of the respective measured value(s) after a start signal for a predetermined detection time and defines this detected actual course (46) in each case as the target course (50) of the corresponding measured value stored in the memory.

6. The monitoring device (1) according to any of the preceding claims, characterized in that a gradient and / or an absolute measured value deviation and / or a standard deviation between the actual course (46) and the target course (50) and / or between the actual course (46) and the error course (52) are used as criterion for the first and / or second defined tolerance (56).

7. Monitoring device (1) according to claim 6, characterized in that the gradient, the absolute measured value deviation, and the standard deviation are used as criteria for the first and / or second defined tolerance (56).

8. The monitoring device (1) according to any of the preceding claims, characterized in that a minimum and / or a maximum over a defined time span of the actual course of the detected measured value with respect to the stored target course (50) and / or the stored error course (52) of the measured value are used as criterion for the defined tolerance (56).

9. The monitoring device (1) according to any of the preceding claims, characterized in that at least two measured values are detected and sensed and the monitoring device uses a behavior and / or a correlation of the at least two measured values between them when comparing the courses and determining whether there is a defect.

10. The monitoring device (1) according to any of the preceding claims, characterized in that, when a defect is determined by the monitoring device (1), an acoustic, visual and / or tactile signal is output by an output unit (60) and / or a corresponding error code is output to the extracorporeal blood treatment device (2).

11. A method (100) for monitoring an extracorporeal blood treatment device, such as a dialysis machine (2), comprising an extracorporeal blood circuit which has an arterial blood line (12) with an arterial patient port (13) and / or at least one venous blood line (14) with a venous patient port (16), and a dialysis fluid system (20) comprising a dialysis fluid supply line (24) and a dialysis fluid drain line (26), wherein during operation of the extracorporeal blood treatment device (2) a detected measured value is sensed, characterized by the steps: selecting (101) the measured value which is suitable for monitoring the blood treatment device (2) and a component of the blood treatment device (2); continuously sensing (102) and thereby detecting the measured value; comparing (106) an actual course (46) of the detected measured value with a target course (50) and with at least one error course (52) of the associated measured value; and determining (114) that there is a defect if, at least in sections, the actual course (46) of the detected measured value deviates from the target course (50) by more than a first defined tolerance (56) and if the actual course (46) of the detected measured value coincides with the error course (52) within a second defined tolerance (56).

12. The method for monitoring according to claim 11, characterized in that the step (106) of comparing comprises the following steps: forming the standard deviation (108; 112) between the actual course (46) of the measured value with the target course (50) and / or the error course (52) of the measured value; comparing (110; 116) the value of the formed standard deviation with a stored target standard deviation.