JP2020116397A - Dialyzing device - Google Patents

Abstract

To provide a dialyzing device that suppresses a risk of adopting an inadequate control default value or an inadequate desired blood pump adjustment value in a special mode.SOLUTION: A dialyzing device includes: a blood pump 4; a dialyzer 2; a venous pressure sensor 6; a displacement liquid line 7; and a control unit 15. The control unit makes the blood pump operate in a first operation mode and a special operation mode. In the special operation mode, a transportation rate of the blood pump is controlled using a default value or is adjusted to a desired value. The default value or desired value is derived from a value determined before starting the special operation mode that currently is starting or corresponds to the value. Before start of the special operation mode, polling is performed with respect to existence of at least one failure. When a failure exists, the start of the special operation mode is inhibited or delayed and/or selection of the default value or the desired value when a failure exists differs from selection when no failure exists.SELECTED DRAWING: Figure 1

Description

The present invention relates to a dialysis apparatus having an extracorporeal blood circuit, a blood pump, a dialyzer, a pressure sensor for measuring a fluid pressure in the extracorporeal blood circuit, a replacement fluid supply line into the extracorporeal blood circuit, and a control unit. Regarding

In the prior art, dialysis processes are known which remove a certain amount of plasma from the blood of a patient on the basis of fluid convection through a dialysis membrane. These processes include hemodiafiltration and hemofiltration. In order to prevent the thickened blood from returning to the patient during these processes, a replacement fluid (substituate) is continuously supplied into the extracorporeal blood circuit.

When the supply of replacement fluid is stopped or reduced at least temporarily for a specific reason, thick blood flows in the venous line and venous connection of the extracorporeal blood circuit. Common reasons for at least temporary interruption or reduction of replacement fluid supply include, for example, changes in the UF rate during the course of treatment or switching from hemodiafiltration to hemodialysis. Further reasons include, for example, performing a pressure hold test, safely stopping the replacement liquid supply, or replacing the concentrate container.

The thickened blood has a high viscosity, which temporarily increases the fluid pressure (ie, blood pressure) in the extracorporeal blood circuit. For example, this can cause a pressure alarm, which is undesirable.

In light of this background art, from WO 2009/144522, a special blood pump operation, for example in which the delivery rate is adjusted in dependence on the venous pressure, in addition to the normal blood pump operation operating at a particular desired delivery rate It is known to provide a blood pump operating mode. This special operation mode starts after a trigger event and ends after a certain length of time has elapsed. Trigger events are associated with reduced replacement fluid supply. For example, a trigger event exists when the venous pressure, the delivery rate of the replacement fluid pump, or the variation of these values exceeds or falls below certain thresholds. In this way, the delivery rate of the blood pump can be temporarily reduced in the special operation mode when the venous pressure exceeds or is likely to exceed the threshold.

International Publication No. 2009/144522

However, such an adjustment may be performed when a further trigger event occurs while still in the special operating mode, or when only a short time elapses between the end of the special operating mode and the next trigger event. Problems can arise. The reason for this is that the desired venous pressure value that adapts the actual venous pressure during the special operating mode is derived from the venous pressure measured before the trigger event. In the special operating mode, this value may be more likely to fluctuate than during normal operation due to the constant inertia of the system, and is stable only after a certain period of time has elapsed since the end of the special operating mode. Therefore, if a further emergence of a special mode of operation is triggered at this stage, it may lead to an undesired desired value.

For example, this may result in the special operating mode repeatedly self-triggering. The reason for this is that if an erroneous desired value is taken in the special operation mode, the delivery rate of the blood pump is significantly different from the desired delivery rate of the normal operation, and changes rapidly after the end of the special mode. This change in delivery rate causes further triggering events, such as short peaks in venous pressure or peaks in the replacement fluid pump, if tied to the delivery rate in the blood pump. The desired venous pressure value may be taken repeatedly.

This can cause pressure alarms to be triggered more frequently, as the frequency of falling below or above the threshold value that triggers the alarm to be determined in normal mode based on adjustments due to erroneous desired values. is there.

It is an object of the present invention to reduce the risk of taking inappropriate control default values or inappropriate desired blood pump adjustment values in special mode.

In view of this background art, the present invention provides an extracorporeal blood circuit, a blood pump, a dialyzer, a venous pressure sensor for measuring venous pressure in the extracorporeal blood circuit, and a substitution liquid supply line into the extracorporeal blood circuit. And a dialysis machine having The dialyzer further comprises a control unit configured to operate the blood pump in the first operating mode and the special operating mode to initiate the special operating mode after the recognition of the trigger event. In the special operating mode, the delivery rate of the blood pump is controlled using the default value or adjusted to the desired value, which is the default value or the desired value before the start of the special operating mode which is currently being started, or the current trigger event. Corresponds to, or is derived from, the value determined before the start of the special operating mode to be started by.

According to the invention, the control unit can be further configured to poll for the presence of at least one fault before the start of the special operating mode. In the presence of a fault, the initiation of the special operating mode is blocked or delayed. Alternatively, or additionally, if a fault is present, the default or desired value selection is different from the corresponding selection in the virtual case where the fault is not present.

In one embodiment, the blood characteristic is determined by a value determined prior to the start of the currently started special operating mode, corresponding to, or derived from, the default or desired value. Can be related. Examples include blood viscosity or hematocrit moieties. In a further embodiment, the instrument value may be the measured value upon which the default or desired value is determined. Examples include blood pump motor current draw or motor power draw. A preferred example is venous pressure. Desired or default values that can be derived from this value can also include these parameters. In the present invention, a default or desired value in the form of one of these parameters, for example motor performance pulling, is derived from a measured value in the form of another of these parameters, for example venous pressure. It is conceivable that this is included in the present invention.

For example, in the special operation mode, the delivery rate of the blood pump may decrease when the measured venous pressure exceeds the desired value, and may increase when the measured venous pressure falls below the desired value. Alternatively, the control unit responds to a value derived from a value measured or determined immediately before the start of the special mode (eg venous pressure or the current power draw of the motor) for controlling the blood pump in the special operating mode. You can choose to use the default value.

In some embodiments, the disorder includes that the blood pump is already operating in a special mode now. In this case, when the selection of the default value or the desired value in the presence of the failure is different from the normal situation, the default value or the desired value can be inherited from the existing special operation mode in the presence of the failure.

In certain embodiments, at least one of the obstacles comprises a specific waiting period after or after the beginning of the phase in which the blood pump was operating in a special operating mode that was previously unexpanded in time. .. In this case, if the selection of the default or desired value in the presence of the fault is different from the selection in the absence of the fault, the default or desired value is inherited from the special operating mode in the phase that was developed earlier in time. be able to. The duration of the waiting period may correspond to the expected blood flow time in the IV line of the extracorporeal blood circuit, or may be deducted or added to a certain percentage (eg 10%, 20%, 30%, 50%). And can be adapted. It is further envisioned that the waiting period may be rigidly fixed by user input or machine-side default values, or based on the particular volumetric throughput of the blood pump.

Alternatively, instead of the end of the temporally developed phase, the start of the temporally developed phase can be used as the starting point of the waiting period. Furthermore, it is also conceivable to use a treatment event as a starting point for a waiting period, which was deployed earlier in time, independent of the stage at which the blood pump was operating in the special operating mode. This starting point includes, for example, a time point at which the measured value (for example, the first venous pressure derivation) exceeds the threshold value, or a time point at which a certain interval exists between the measured value (for example, the venous pressure) and the expected value.

In certain embodiments, the disorder comprises an initial venous pressure derivation in the presence of a trigger event exceeding a threshold. This is equivalent to an unstable condition in which a suitable default value or a suitable desired value cannot be determined. In this case, too, the triggering of the special operating mode is blocked or the default or desired value of the special operating mode developed earlier in time is adopted for the new special operating mode.

Blocking triggers may displace triggers when the trigger event is maintained and faults are cleared (continuing to be polled periodically or continuously), so the displacement of the trigger in the special operating mode is It is a lower case.

It is also possible to poll multiple faults cumulatively. Furthermore, it is also conceivable to poll for only one or two faults.

In some embodiments, a default or desired value is derived from a measured value, such as venous pressure prior to initiation of the special mode. For example, a venous pressure within 60 seconds, 30 seconds or 10 seconds before the occurrence of a trigger event or the start of the special operation mode, optionally before or less than 1 second before the occurrence of the trigger event or the start of the special operation mode You can take measurements. It is also conceivable to take the average value of a plurality of measurement values measured during this period.

In certain embodiments, the blood pump operates at a predetermined flow rate expansion, and in particular at a constant flow rate or speed, before and/or after the special operating mode.

For example, a trigger event may be above or below an expected value of a measurement, such as venous pressure. This is the case, for example, when ultrafiltration is limited or set, but there is still thickened blood in the line section upstream of the opening point of the substitution fluid line and downstream of the dialyzer. It can be associated with reduced rates or switching from hemodiafiltration to hemodialysis. Furthermore, this may be due to, for example, performing pressure retention tests on the displacement liquid circuit, safely stopping the displacement liquid supply (eg, fluctuations in conductivity or detection of bubbles in the displacement liquid), or replacing the concentrate container in the framework of replacement. It can also be related to interruption of liquid supply. Venous pressure can be reduced when highly diluted blood is present in at least one segment of the venous line. This is the case, for example, when ultrafiltration is limited or set but ultrafiltration is still present in the line section upstream of the opening point of the substitution fluid line and downstream of the dialyzer. It can be associated with a decrease in rate or transmembrane pressure, or the switch from hemodialysis to hemodiafiltration. Furthermore, this can also be related to the delivery of a bolus into the extracorporeal blood circuit by means of a substitution fluid, for example in order to be able to carry out a particular measuring procedure.

Further, the trigger event can be a stop, a decrease, a start or an increase in replacement fluid administration. This can be in the same relationship as described above for trigger events above or below the venous pressure threshold. In addition, the substitution pumps involved in the delivery of substitution fluid into the extracorporeal blood circuit are located in the substitution fluid line so that changes in the delivery rate of the blood pump caused by treatment can also trigger such events. The delivery rate is often tied to the delivery rate of the blood pump.

The special operating mode may continue for a long time until manually terminated by the user. Alternatively or additionally, the duration of the special operating mode may approximate or adapt to the expected blood flow time in the venous line of the extracorporeal blood circuit during normal operation of the blood pump. This duration may be assumed, for example, or may add a security addition of at least 10%, 20% or 50%, but optionally less than 100%. For example, the extracorporeal blood circuit during normal operation of the blood pump, based on the delivery rate of the blood pump before the start of the special operating mode, and the known structural type of the extracorporeal blood circuit (length of individual sections, diameter, total volume, etc.). Of blood flow time through the venous line can be made. Typical predicted durations include, for example, periods of 1-10 minutes, or 10-60 seconds, or 1-10 seconds.

It is also conceivable to configure the control unit such that the waiting period correlates with the duration of the special operating mode.

In certain embodiments, the replacement fluid supply line opens into the venous line of the extracorporeal blood circuit. Therefore, the substitution liquid supply line is a line for post-dilution. This line can open into the extracorporeal blood circuit upstream or downstream of the pressure sensor. Alternatively, the replacement fluid supply line can be opened to the arterial line of the extracorporeal blood circuit. However, in general, changes in venous pressure caused by variations in predilution are less than changes in venous pressure caused by variations in postdilution.

The replacement fluid supply line can include a replacement fluid pump that is responsible for delivering the replacement fluid into the extracorporeal blood circuit.

In some embodiments, changes in the replacement liquid supply rate during the course of the special mode of operation are prevented or allowed only within a predetermined range. This measure makes it possible to prevent the occurrence of a trigger event, for example, below the pressure limit, during the special mode. For example, bolus delivery during the special mode can be blocked in this way. Furthermore, this measure can prevent the occurrence of a trigger event at the end of the special mode. The reason for this is that if the displacement rate increases during the special mode of operation, the pressure diminishes due to blood dilution and the delivery rate of the blood pump increases. Thereafter, this transport rate changes abruptly at the end of the special operation mode.

In some embodiments, changes in the replacement liquid supply are prevented or allowed only within a predetermined range within a certain waiting period after the end of the special operation mode. This measure can prevent the occurrence of a trigger event immediately after the end of the special mode. Since it is possible to prevent a large change in the ratio of the replacement rate and the blood flow, it is possible to prevent the occurrence of an undesired pressure alarm. The duration of the waiting period may correspond to the expected blood flow time in the IV line of the extracorporeal blood circuit, or may be deducted or added to a certain percentage (eg 10%, 20%, 30%, 50%). And can be adapted. It is further envisioned that the waiting period may be rigidly fixed by user input or machine-side default values, or based on the particular volumetric throughput of the blood pump.

The configuration of the control unit according to the invention is based on the fact that the control unit is connected to the relevant components of the dialyzer and the algorithms enabling the control of the blood pump according to the invention are stored in the control unit.

Further details and advantages of the invention can be obtained from the figures and embodiments described below. These are shown in the figure below.

1 is a schematic view of a dialysis device according to the present invention. FIG. 2 is a schematic diagram of the time evolution of the delivery rate of the replacement fluid pump, the delivery rate of the blood pump and the venous pressure in the dialyzer according to the prior art. FIG. 3 is a schematic diagram of the time evolution of the delivery rate of the replacement fluid pump, the delivery rate of the blood pump and the venous pressure in the dialyzer according to the present invention.

FIG. 1 is a schematic diagram of a dialysis device according to the present invention. The dialyzer has an extracorporeal blood circuit 1 and a dialyzer 2. The dialyzer 2 can be, for example, a hollow fiber dialyzer.

A blood pump 4 is located in the arterial line 3 of the extracorporeal blood circuit 1. The blood pump 4 can be, for example, a peristaltic pump. A venous pressure sensor 6 is located in the venous line 5 of the extracorporeal blood circuit. Further, a post-dilution line 7 that opens into the venous line 5 of the extracorporeal blood circuit is provided at an opening point 8 upstream of the venous pressure sensor 6. A substitution liquid pump 9 is located in the post-dilution line 7.

The extracorporeal blood circuit 1 communicates with a dialysis fluid circuit (dialysis fluid circuit) 10 via a membrane arranged in the dialyzer 2. The illustrated dialysis machine embodiment can be configured according to the system settings of hemodialysis, hemodiafiltration, or hemofiltration. In the case of hemodialysis and hemodiafiltration, the dialysate side of the dialyzer 2 is supplied with fresh dialysate via the part 11 of the dialysate circuit 10 located upstream of the dialyzer 2. The spent dialysate, and optionally the ultrafiltrate, exits via a portion 12 of the dialysate circuit 10 located downstream of the dialyzer 2. In the case of hemofiltration, the supply of dialysis fluid to the dialysate side of the dialyzer 2 is omitted and only the ultrafiltrate flows out via the part 12 of the dialysate circuit 10 located downstream of the dialyzer 2. The part 11 of the dialysate circuit 10 located upstream of the dialyzer 2 is not used in all operating modes of the machine and is therefore only shown in dashed form in the figure. In the illustrated embodiment, dialysate pumps 13 and 14 are located both upstream and downstream of dialyzer 2 in dialysate circuit 10. However, of course, different arrangements of these pumps or omission of at least one of these pumps is also conceivable.

The post-dilution line 7 branches off from the part 11 of the dialysate circuit 10 upstream of the dialyzer 2 and thus obtains the replacement liquid from this line, or into a separate reservoir for replacement liquid not shown in more detail. Reach

The control unit 15 in the illustrated embodiment communicates with the blood pump 4, the venous pressure sensor 6 and the replacement fluid pump 9. The control unit 15 adjusts the delivery rate of the blood pump 4 and receives the signal of the venous pressure sensor 6. The control unit 15 adjusts the blood pump 4 so that a specific blood delivery rate is selected in normal operation. The delivery rate is selected, for example, so that the transmembrane pressure in the dialyzer 2 allows the achievement of therapeutic purposes. Details regarding the selection of transport rates in normal operation are known in the prior art and are not the subject of this patent application.

The control unit 15 stores an algorithm for temporarily starting the so-called special operating mode of the blood pump 4 after the recognition of the trigger event. In this special operation mode, the delivery rate of the blood pump is adjusted based on the venous pressure measured by the venous pressure sensor 6, the actually measured venous pressure is compared with a desired value, and based on the comparison result. The pump will be adjusted. Therefore, in the special operation mode, the delivery rate of the blood pump decreases when the measured venous pressure exceeds the desired value, and rises when the measured venous pressure falls below the desired value.

Therefore, in this embodiment, the adjustment of the pump rate based on the venous pressure will be described. However, of course, the present invention is not limited to using venous pressure as the desired value. Furthermore, it should be understood that the present invention is not limited to regulation, but rather regulation that uses default values for determining pump rate, such as venous pressure, or motor power draw of the blood pump immediately prior to the special mode. Alternatively, it can be included. Of course, the indications made in connection with an embodiment also apply to these other embodiments.

In this embodiment, the desired value is derived from the pressure measured by the venous pressure sensor 6 before the start of the special mode. For example, a single value measured at the venous pressure sensor 6 one second before the start of the special mode can be used as the desired value, but this is only one example and the selection of this desired value is It does not represent an essential element of form.

In this embodiment, a trigger event is assumed to be above or below the pressure threshold measured at the venous pressure sensor 6. Similarly, this selection is only an example and does not represent an essential element of this embodiment. It is equally conceivable that the control unit 15 is further in communication with the replacement fluid pump 9 and that stop, decrease, start or increase of replacement fluid administration is selected as the trigger event. These events may, for example, slow down the displacement fluid pump 9 when the dialyzer 2 is clogged (often also referred to as coagulation), or triggers an alarm of substitution fluid supply (dialysis fluid, for example, when performing a hydraulic pressure hold test). Replacement fluid pump 9 that does not affect the blood pump 4 during conductivity or temperature, non-physiological) or during change of treatment type (hemofiltration after hemofiltration, hemodiafiltration after hemofiltration, or vice versa). Corresponding to the stop of.

In this embodiment, the duration of the special mode of operation corresponds to a safety benefit of +30% of the expected blood flow time in the venous line during the delivery rate before the start of the special mode of operation. Similarly, this selection is also an example and does not represent an essential element of this embodiment.

According to the invention, it is also possible for the control unit to carry out further polling with the stored algorithm after the recognition of the trigger event before the start of the special operating mode of the blood pump 4. This polling concerns whether there are obstacles that oppose the initiation of a special model, or at least require adaptation in the selection of the desired value.

Such obstacles include that the blood pump 4 is already operating in the special mode at present. In this case, the duration of the special operation mode is reliably extended, for which a further special operation mode is started. However, the desired value of venous pressure is not fixed based on the measured value of venous pressure measured during the existing special operating mode, and thus one second before the start of the further special operating mode. Taken over from the special operating mode.

Further obstacles include the blood pump 4 being in normal operation for only a short period of time, for example because the blood pump 4 has just finished operating in a special mode of operation. In this regard, this obstacle includes, for example, that the series of two stages in which the blood pump 4 operates in the special operating mode are too close in time. In this case, the triggering of the special operating mode is blocked, or the desired value of the special operating mode developed earlier in time is used for the new special operating mode. In this embodiment, the duration of the waiting period is selected to correspond to the expected blood flow time in the venous line of the extracorporeal blood circuit. This flow time is estimated by reference to the delivery rate of the blood pump before the start of the (past) special mode of operation and the known construction type of the venous line. This selection is an example and does not represent an essential element of this embodiment. For example, a specific volumetric flow rate at the blood pump 4 could simply be used, or a constant duration could simply be used.

Further obstacles include the initial venous pressure derivation exceeding a threshold in the presence of a trigger event, ie when a strong drift is present and the system is not stable. If this is the case, it is doubtful whether a suitable desired value can be determined. In this case, too, the triggering of the special operating mode is blocked or the desired value of the special operating mode developed earlier in time is used for the new special operating mode.

As a result, the blocking of the special operating mode trigger also causes a displacement of the special operating mode trigger, i.e. the obstruction is removed if the trigger event (e.g. exceeding the venous pressure limit) is maintained.

In this embodiment, these faults are cumulatively polled, but the invention contemplates that only one or two of these faults may be polled and is included in the present invention.

FIG. 2 is a schematic diagram of the delivery rate of the replacement fluid pump 20, the delivery rate of the blood pump 21 and the venous pressure 22 in the dialyzer over time according to the prior art. From a structural point of view, this dialysis device can have the same elements as described in connection with FIG. The only difference from the present invention is that the control unit does not have any further polling after the recognition of the trigger event before the start of the special operating mode of the blood pump.

As can be seen, in the illustrated example, a change in replacement rate is used as a prior art trigger event (reference numeral 23). For example, in this example, a pressure hold test of the displacement fluid system would trigger a special mode of operation. Displacement failure results in an increase in venous pressure due to the presence of thickened blood in the venous line (reference number 24). However, in the special mode, the blood pump is controlled depending on the venous pressure, and it is desirable that the remaining venous pressure has a desired value (reference numeral 25). No. 26) is lowered. In the prior art, the desired value before the start of the special mode is fixed on the basis of the venous pressure. As can be seen from the curves 21 and 22, during the special operating mode the pressure development is subject to a certain inertia. In this respect, the actual venous pressure fluctuates before and after the desired value.

At this point, if a further trigger event occurs (eg in the form of a bolus delivery (reference number 27)) while the special operating mode still exists, the new special mode is started. This special mode differs from the existing special modes by the fact that the magnitude of the desired value is fixed with reference to the venous pressure before the start of the current further special mode (reference number 28). However, this desired value differs to a large extent from the venous pressure expected in normal operation of the blood pump due to the variations mentioned above. In this regard, with respect to the figure, the blood pump rate drops to the lowermost dashed line, which also reduces the venous pressure to the dashed line. The reason for this is that this desired value is not the initial value before the first event that would be taken as the desired desired value, but the value on the centerline of the curve 21 of FIG. That's why.

As a result, at the end of the special mode (reference numeral 29), the blood pump rate increases significantly (reference numeral 30). According to FIG. 2, the rate of the displacement pump in the system is tied to the rate of the blood pump so that at the end of the special operating mode (reference numeral 31) the rate of the displacement pump also rises sharply. This can result in unwanted special mode self-triggering.

FIG. 3 is a schematic diagram of the time evolution of the delivery rate of the replacement fluid pump 20, the delivery rate of the blood pump 21 and the venous pressure 22 in the dialyzer according to the present invention. This dialyzer has the same structure as the dialyzer underlying the representation according to FIG. Here, it is only possible for the control unit to perform further polling after the recognition of a trigger event, before the start of the special operating mode of the blood pump.

In FIG. 3, the reference numbers corresponding to the corresponding events or features of FIG. 2 are used. Corresponding explanations can also be taken over accordingly.

As can be seen with reference to the figure, before the start of the further special mode, polling is performed by the control unit after the presence of the fault after the recognition of the second trigger event (reference number 27). Such a disturbance is perceived as if the blood pump is currently already operating in a special mode. As a result, a new desired value is not selected for the venous pressure (reference numeral 28 in FIG. 2) for the second special mode as in the case of FIG. 2, and the existing special operation mode (reference numeral 32) is not selected. The desired value is carried over. This desired value closely matches the venous pressure expected in normal operation of the blood pump. As a result, the blood pump delivery rate does not have to change significantly at the end of the special mode, and undesirable self-triggering of the system is avoided.

1 extracorporeal blood circuit 2 dialyzer 3 arterial line 4 blood pump 5 venous line 6 venous pressure sensor 7 post-dilution line 8 opening point 9 substitution fluid pump 10 dialysis fluid circuit 11 part 12 part 13 dialysate pump 14 dialysate pump 15 control unit

Claims (15)

A dialyzer having an extracorporeal blood circuit, a blood pump, a dialyzer, a venous pressure sensor, a replacement fluid line, and a control unit,
The control unit is configured to operate the blood pump in the first operation mode and the special operation mode, and start the special operation mode after the recognition of the trigger event, in the special operation mode, the delivery rate of the blood pump. Is controlled with a default value or adjusted to a desired value, said default value or said desired value being derived from or corresponding to a value determined prior to the start of the currently started special operating mode. In the dialysis machine
The control unit is further configured to poll for the presence of at least one fault before the start of the special operating mode, in the presence of the fault the start of the special operating mode is blocked or delayed, and / Or selection of the default value or the desired value in the presence of the obstacle is different from the selection in the absence of the obstacle,
A dialysis machine characterized by the above. The value, the desired value or the default value determined before the start of the currently operating special operating mode is a blood characteristic such as blood viscosity or hematocrit portion, or motor current draw or motor power draw of the blood pump. The dialysis device according to claim 1, which is an instrument value such as or venous pressure. The failure includes that the blood pump is currently already operating in the special mode,
The dialysis device according to claim 1 or 2. If the blood pump is currently already operating in the special mode, the default value or the desired value is inherited from the existing special operation mode,
The dialysis device according to claim 3. At least one of the obstacles comprises a specific waiting period after the start or after the step of operating the blood pump in the previously unattained special operating mode that has been deployed in time.
The dialysis device according to any one of claims 1 to 4. The default value or the desired value is inherited from the special operating mode during the phase, which was expanded in time.
The dialysis device according to claim 5. The disorder includes a first derivation of a measurement, such as the venous pressure, in the presence of the trigger event exceeding a threshold.
The dialysis device according to any one of claims 1 to 6. The default value or the desired value is derived from the measured value such as the venous pressure before the start of the special mode,
The dialysis device according to any one of claims 1 to 7. The control unit is configured such that the blood pump operates at a predetermined flow rate expansion before and/or after the special operation mode, in particular at a constant flow rate or a constant speed.
The dialysis device according to any one of claims 1 to 8. The trigger event is above or below a threshold, or a slope of a measured value, such as the venous pressure, and/or stop, decrease, start or increase of replacement fluid administration,
The dialysis device according to any one of claims 1 to 9. The control unit is configured to approximate or adapt the duration of the special operating mode to an expected blood flow time in the venous line of the extracorporeal blood circuit during normal operation of the blood pump,
The dialysis device according to any one of claims 1 to 10. The control unit is configured such that the waiting period correlates to the duration of the special operating mode.
The dialysis device according to any one of claims 1 to 11. The replacement liquid supply line opens into the venous line of the extracorporeal blood circuit,
The dialysis device according to any one of claims 1 to 12. The control unit is further configured to prevent a change in the supply rate of the replacement liquid during the course of the special operation mode, or to be allowed only within a predetermined range.
The dialysis device according to any one of claims 1 to 13. The control unit is further configured to prevent a change in the supply of the replacement liquid within a certain waiting period after the end of the special operation mode, or to be allowed only within a predetermined range.
The dialysis device according to any one of claims 1 to 14.

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