Device for dialysis treatment

Abstract

The invention relates to a device for dialysis treatment, in particular for peritoneal dialysis, comprising: a discontinuous first pump and a discontinuous second pump which can be switched by means of at least two valves; and a control device for generating a continuous volumetric flow of dialysate, characterized in that the control device is designed to carry out at least one of the following steps: a) during a switching time of at least one of the valves, at least one pressure measurement is suspended; b) during the switching time of at least one of the valves, computationally compensating the share of the result of the pressure measurement based on the device characteristic; c) postponing the valve switching time point of the second pump so that the valve switching time point of the second pump is inconsistent with the valve switching time point of the first pump; and d) adaptively delaying the valve switching time of the second pump in such a way that the valve switching time does not coincide with the valve switching time of the first pump, the time being determined on the control device, preferably using an optimization algorithm, to which the valve switching time of the second pump is delayed.

Description

Technical Field

[0001] The invention relates to an apparatus for dialysis treatment, in particular for peritoneal dialysis, which is configured to provide a continuous volume flow of dialysis fluid by means of two discontinuously operating pumps. The invention also relates to a corresponding method. Background Art

[0002] When the dialysate is continuously conveyed by means of an apparatus for extracorporeal blood treatment, in particular an apparatus for peritoneal dialysis, by means of which the dialysate is conveyed directly into and out of the patient's abdominal cavity, it is important to always correctly adhere to the negative pressure or overpressure provided for the conveying, since deviations therefrom can often be accompanied by discomfort on the part of the patient and can even lead to injuries to the peritoneum. In particular, in pediatric treatment, the dialysate should be conveyed into and out of the patient as gently as possible, so that, for example, the conveying takes place at a lower negative pressure than in adult treatment.

[0003] In addition, the transfer time of the dialysate to be delivered should be as short as possible so that the prescribed times for the inflow phase, the dwell time and the outflow phase are followed as accurately as possible. In this case, it is advantageous that the working pump is always operated with the highest possible flow rate.

[0004] Furthermore, disruptions in the pumping process of the dialysate into and out of the patient should in principle be avoided.

[0005] In practice, it has proven problematic to always provide a continuous, prescribed volume flow of dialysate, particularly during the outflow phase of a peritoneal dialysis treatment.

[0006] Especially in the outflow phase of peritoneal dialysis treatment, high requirements are imposed, since the required negative pressure is, for example, at the level of -100 mbar and the negative pressure (and possibly undesired deviations therefrom) can be clearly felt by the patient. In pediatric peritoneal dialysis treatment, the preset pressure is further reduced to a minimum of -80 mbar, which further increases the requirements. Summary of the invention

[0007] Against this background, the present invention is based on the object of alleviating or even completely eliminating the problems known from the prior art. In particular, the present invention is based on the object of realizing a device and a method by means of which a continuous volume flow of the dialysate can be reliably achieved even in the case of the mentioned high demands.

[0008] This object is achieved by a device having the features of claim 1 and by a method having the features of claim 10. Advantageous developments of the invention are the subject matter of the dependent claims.

[0009] Accordingly, an apparatus for extracorporeal blood treatment, in particular for peritoneal dialysis, is proposed, which has a first and a second discontinuous pump switchable by means of at least two valves and a control device for generating a continuous volume flow of dialysis fluid.

[0010] According to the present invention, the control device is designed to perform at least one of the following steps: a) suspending at least one pressure measurement during the switching time of at least one of the valves; b) computationally compensating for a portion of the result of the pressure measurement based on device characteristics during the switching time of at least one of the valves; c) postponing the valve switching time of the second pump so that the valve switching time of the second pump is inconsistent with the valve switching time of the first pump; and d) adaptively postponing the valve switching time of the second pump so that the valve switching time is inconsistent with the valve switching time of the first pump, wherein in terms of control, an optimization algorithm is preferably used to determine the following time point, and the valve switching time point of the second pump is postponed to the said time point.

[0011] In practice, a pump cassette is usually used which has two pump chambers, which are respectively associated with a first pump and a second pump and which are fluidically connected to each other via at least one valve.

[0012] If, for example, the first pump is operating and conveying dialysate, the second pump is usually switched on while the first pump is still operating. To this end, the valve connecting the first pump to the second pump fluid is opened. However, as soon as the valve is opened, a pressure balance occurs between the first pump and the second pump or their pump chambers. This causes the measured conveying pressure of the first pump to be distorted, and the first pump, which is then in operation, stops.

[0013] Since the delivery pressure of the first pump is distorted by switching on the second pump, the continuous volume flow of the dialysate achieved by the coordinated action of the first pump and the second pump is undesirably interrupted.

[0014] By means of the invention, such a distortion of the delivery pressure can preferably be prevented from occurring and / or a measured change in the delivery pressure can be detected as a distortion of the delivery pressure caused by switching on the second pump and / or can be subsequently compensated or ignored.

[0015] Preferably, the present invention avoids as much as possible the effects of distortions in the delivery pressure of the first pump caused by the switching on of the second pump on the measurement of the delivery pressure (for example by suspending the pressure measurement during the switching on period or by computational compensation of the pressure changes caused by the switching on) and / or on the operation of the first pump and / or the second pump (for example undesired switching off of the first pump due to a change in the measured delivery pressure of the first pump).

[0016] The device according to the invention therefore preferably makes it possible to avoid disruptive pressure pulses due to switching of at least one valve associated with the first pump or the second pump.

[0017] In this case, the invention is not restricted to a specific delivery system or pump system, but can be used in any design with two discontinuous pumps in which a continuous volume flow of the dialysate is to be achieved.

[0018] For example, in the device according to the invention, active pressure measurement can be performed in the measuring section, which may be disturbed by the valve line or the patient clamp line. Therefore, the invention includes the case where the delivery pressure of the first pump and / or the second pump is performed in the measuring section.

[0019] In other words, the present invention can represent a method for avoiding and / or compensating for pressure fluctuations (e.g. pressure pulses) in a device for dialysis treatment, wherein the focus of the invention is preferably on the components (valves) acting on the fluid and their switching. Thus, according to the present invention, it is preferred to influence the actuators of the flow path, such as valves, clamps or any other element suitable for regulating the flow of the fluid, rather than on the delivery system (e.g. pump) itself.

[0020] The method steps which can be executed by the control device of the device according to the invention are described in detail below.

[0021] According to one embodiment of the invention, the control device is designed to execute at least the following steps: a) during a switching time of at least one of the valves, suspend at least one pressure measurement.

[0022] In other words, preferably, the measurement of the delivery pressure of the first pump is interrupted during the valve switching time period of the first pump and / or the second pump. In this way, distortions or artifacts of the measured delivery pressure due to valve switching do not enter into the measurement of the delivery pressure.

[0023] The measurement of the delivery pressure is suspended, preferably until the system being monitored has calmed down.

[0024] The advantage of this method approach is that the method steps are simple to implement.

[0025] According to one specific embodiment of the invention, the control device is designed to carry out at least the following steps: b) computationally compensating a component of the result of the pressure measurement that is based on the system characteristic during a switching time of at least one of the valves.

[0026] In the described design, the control device preferably detects: switching of at least one valve connecting the first pump and the second pump fluid, for example waiting for coupling or switching on the second pump, and preferably compensates for the effect of the switching on the measurement of the delivery pressure of the first pump by using a saved or learned characteristic or a saved or learned pressure change curve.

[0027] For the learning process, the first pump or the second pump can be loaded at different speeds, for example, at the end of the equipment process when filling the cassette. During the movement, the relevant valve stroke is established and the pressure fluctuations generated thereby are recorded. From the recording, the time, the switching speed and the pressure pulse can be determined. The parameters can be used in the further development of the treatment.

[0028] The advantage of this method approach is that the pressure measurement does not have to be interrupted, but rather the delivery pressure of the pump(s) can be measured continuously.

[0029] The advantages can also be achieved if, according to one embodiment of the present invention, the control device is designed to perform at least the following steps: c) delaying the valve switching time of the second pump so that the valve switching time of the second pump does not coincide with the valve switching time of the first pump. In other words, the valve switching time of the second pump is preferably separated from the valve switching time of the first pump in time.

[0030] Preferably, the control device is designed in such a way that the first pump completes its pump stroke and the second pump is switched on with a delay after the pump stroke.

[0031] The switching on of the second time period can take place, for example, after the expiration of a fixed delay time period, for example a few milliseconds.

[0032] According to one embodiment of the present invention, the control device is designed to perform at least the following steps: d) adaptively delaying the valve switching time point of the second pump so that the valve switching time point is inconsistent with the valve switching time point of the first pump, wherein on the part of the control device, an optimization algorithm is preferably used to determine the following time point, and the valve switching time point of the second pump is delayed to the said time point.

[0033] In this case, the term "adaptive" postponement is preferably understood to mean that the time period by which the valve switching time of the second pump is delayed or postponed relative to the valve switching time of the first pump and / or the end of the pump stroke of the first pump is not fixed or constant, but is determined individually for the given conditions existing at the current time. The duration of the determined time period is therefore preferably individually adapted or adapted to the given conditions existing at the current time.

[0034] Preferably, at least one of the following parameters is taken into account, preferably by the optimization algorithm, when determining the duration of the time period:

[0035] · Optimally operate the pump flow rate (pump speed)

[0036] Patient fill level (volume of dialysate in the patient)

[0037] The volume of the pump chamber finally delivered by the optimally working pump

[0038] Type of treatment (adult or pediatric treatment)

[0039] By means of this embodiment, interruptions in the pressure measurement can likewise be avoided and the measured values ​​of the delivery pressure of the first pump and / or the second pump can be recorded continuously.

[0040] Furthermore, preferably, a maximum flow rate (pump speed) of the first pump and / or the second pump can be achieved.

[0041] Even at relatively low flow rates (pump speeds), measurable liquid displacements and pressure pulses, in other words undesirable distortions of the measured delivery pressure, are reliably eliminated.

[0042] In summary, the following advantages can be achieved with the help of the present invention: improved provision of a continuous volume flow of dialysate, in particular during the outflow phase of a peritoneal dialysis treatment, reduction of erroneous reports due to distorted pressure measurements; improved adaptation of the pump control to the outflow behavior of the individual patient and increased performance of the dialysis device in pediatric treatment.

[0043] According to one embodiment of the invention, the control device is designed to carry out at least one of the steps in an inflow phase of the peritoneal dialysis treatment and / or in a outflow phase of the peritoneal dialysis treatment.

[0044] According to one embodiment, the control device is designed to open the valve connecting the first pump to the second pump fluid only when the second pump has completely completed the last pump stroke and / or is not working. This prevents the pressure balance generated by the valve opening from distorting the measurement of the delivery pressure of the first pump. An example of such a valve connecting the first pump to the second pump fluid is, for example, Figure 1 and Figure 2 Valves V1 and V3 in.

[0045] According to one embodiment, the first pump and the second pump each cooperate with a pump chamber formed in a disposable article (also called disposable or "disposable") to convey the fluid, and the at least two valves are preferably each a component of the disposable article.

[0046] According to one embodiment, during the computational compensation process, a pressure profile from a database that accompanies system characteristics, in particular valve switching, is used in order to thereby identify and compensate for a proportion of the result of a pressure measurement during the switching time of at least one of the valves that is based on the system characteristic.

[0047] The pressure profile can be created with the aid of the learning process described above.

[0048] According to one embodiment, the control device is designed to use an optimization algorithm to determine or precalculate the following time point, the valve switching time point of the second pump should be postponed to or is postponed to the said time point, wherein the optimization algorithm takes into account at least one of the following parameters at a given time point: the flow rate of the first pump and / or the second pump, preferably the flow rate of the pump of the first pump and the second pump that is operating at this time point; the last pump chamber volume delivered by the first pump and / or the second pump, preferably the flow rate of the pump of the first pump and the second pump that is operating at this time point; the volume and type of treatment being performed in the patient.

[0049] After precalculating the desired valve switching time of the second pump by means of the control device or the optimization algorithm, the control device preferably controls the second pump such that the valve switching time of the second pump falls at the precalculated time.

[0050] According to one specific embodiment, the optimization algorithm is designed to minimize a time delay between a valve switching time of the second pump for starting a pump stroke of the second pump and a valve switching time of the first pump at the end of a pump stroke of the first pump.

[0051] Step c) may include: starting from the valve switching time point of the first pump, delaying the valve switching time point of the second pump by a fixed delay time period, so that the valve switching time point of the second pump does not coincide with the valve switching time point of the first pump, but is separated from the valve switching time point of the first pump in time. The fixed delay time period may be stored in a database, for example.

[0052] In addition, step d) may include: starting from the valve switching time of the first pump, postponing the valve switching time of the second pump by the following delay time period, wherein the delay time period is variable and preferably determined by an optimization algorithm for a specific or each valve switching process individually, so that the valve switching time of the second pump is inconsistent with the valve switching time of the first pump.

[0053] Another aspect of the present invention relates to a method for generating a continuous volume flow rate of a dialysate by means of a device for dialysis treatment, preferably a device for dialysis treatment according to the present invention, the device having a discontinuous first pump and a discontinuous second pump that can be switched by means of at least two valves, wherein the method comprises at least one of the following steps: a) pausing at least one pressure measurement during the switching time of at least one of the valves; b) computationally compensating a portion of the result of the pressure measurement based on device characteristics during the switching time of at least one of the valves; c) postponing the valve switching time of the second pump so that the valve switching time of the second pump does not coincide with the valve switching time of the first pump; and d) adaptively postponing the valve switching time of the second pump so that the valve switching time does not coincide with the valve switching time of the first pump, wherein an optimization algorithm is preferably used to determine the following time point, to which the valve switching time of the second pump is postponed.

[0054] All features disclosed above in the context of the device according to the invention are likewise applicable to the method according to the invention, even if they are not explicitly explained again to avoid redundancy, and vice versa.

[0055] In the method according to the invention, at least one of the steps can be performed in an inflow phase of a peritoneal dialysis treatment and / or in an outflow phase of a peritoneal dialysis treatment.

[0056] According to one embodiment, the method according to the invention provides that the valve fluidically connecting the first pump to the second pump is opened only when the second pump has completely completed the last pump stroke and / or is not operating and / or the measurement of the delivery pressure of the first pump is completed.

[0057] According to one embodiment, the method according to the invention provides that during the computational compensation, a pressure profile from a database associated with a system characteristic, in particular associated with a valve switching, is used in order to thereby identify and compensate for a component of the result of a pressure measurement during a switching time of at least one of the valves that is based on the system characteristic. For example, the computational compensation can include subtracting the pressure profile associated with the valve switching from the measured pressure profile.

[0058] According to one embodiment, in the method according to the present invention, an optimization algorithm is used to determine or precalculate the following time point, and the valve switching time point of the second pump is postponed to the said time point, wherein the optimization algorithm takes into account at least one of the following parameters at a given time point: the flow rate of the first pump and / or the second pump, preferably the flow rate of the pump of the first pump and the second pump that is operating at this time point; the last delivered pump chamber volume of the first pump and / or the second pump, preferably the flow rate of the pump of the first pump and the second pump that is operating at this time point; the volume and type of treatment performed in the patient.

[0059] The optimization algorithm can be designed to minimize the time delay between a valve switching time of the second pump for starting a pump stroke of the second pump and a valve switching time of the first pump at the end of a pump stroke of the first pump.

[0060] According to one embodiment of the method according to the present invention, step c) includes: starting from the valve switching time point of the first pump, postponing the valve switching time point of the second pump by a fixed delay time period, so that the valve switching time point of the second pump is inconsistent with the valve switching time point of the first pump.

[0061] According to one embodiment of the method according to the present invention, step d) includes: starting from the valve switching time point of the first pump, the valve switching time point of the second pump is postponed by the following delay time period, wherein the delay time period is variable and preferably determined individually for each valve switching process by an optimization algorithm, so that the valve switching time point of the second pump is inconsistent with the valve switching time point of the first pump.

[0062] At this point it should be pointed out that the present disclosure should be understood as including that the features disclosed within the scope of a specific feature combination or embodiment may also be claimed individually or in other feature combinations and that the disclosure is in no case limited to the explicitly mentioned feature combinations. For the sake of brevity and concise presentation only, not all feature combinations included in the present disclosure are explicitly disclosed.

[0063] Furthermore, it should be understood that when an element is referred to in the singular with the article “a” or “an”, this should not be interpreted as “exactly one”, but rather, designs having the plural form of the element are also covered by the present disclosure, and vice versa. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Other advantages, effects and features of the present invention are apparent from the following description of embodiments of the present invention with reference to the accompanying drawings, in which the same reference numerals represent the same or similar components. In this case, it is shown:

[0065] Figure 1 A pump cassette designed as a disposable part according to a first embodiment which can be used within the scope of the present invention is shown;

[0066] Figure 2 A pump cassette designed as a disposable part according to a second embodiment which can be used within the scope of the present invention is shown;

[0067] Figure 3 A flow chart is shown which shows the method steps which are respectively carried out by a first pump and a second pump within the scope of an embodiment of the present invention, and

[0068] Figure 4An example of an optimization algorithm used within the scope of an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0069] exist Figure 1 1 shows a first embodiment of a box. The box has a hard part 1 made of plastic, in which fluid paths and coupling areas are introduced as corresponding recesses, cavities and channels. The hard part can be made as an injection molded part or a deep-drawn part, for example. The coupling plane of the hard part 1 is covered by a flexible film 2, which is welded to the hard part in the edge region. By squeezing the coupling surface of the box and the dialysis machine, the flexible film 2 and the hard part are squeezed. By squeezing the flexible film and the web area of ​​the hard part, the fluid paths in the box are separated from each other in a fluid-tight manner.

[0070] The cassette has interfaces for connecting the cassette to the rest of the fluid path. On the one hand, an interface 3 for connecting to the outflow and an interface 4 for connecting to the connector are provided. Corresponding hose elements can be arranged at the interfaces, which are Figure 1 In addition, the box has a plurality of interfaces 5 for connecting the dialysate container. Here, the interface 5 is configured as a connector, for example, to which a corresponding connector element can be connected.

[0071] The interfaces are respectively connected to the fluid paths inside the box. A valve area is provided in the fluid path. In the valve area, the flexible membrane 2 can be pressed into the hard component 1 via a valve actuator on the machine side, so that the corresponding fluid path is cut off. Here, the box first has a corresponding valve for each interface, via which the interface can be opened or closed. Here, the interface 3 for the outflow part is associated with a valve V10, and the interface 4 for the patient connector is associated with a valve V6. The interface 5 for the dialysate container 10 is associated with valves V11 to V16.

[0072] In addition, pump chambers 6 and 6' are provided in the box, which can be operated by the corresponding pump actuator of the dialysis machine. The pump chambers 6 and 6' are concave recessed portions in the hard component 1, which are covered by the flexible membrane 2. The membrane can now be pressed into the pump chambers 6 and 6' or pulled out again from the pump chambers by the pump actuator of the dialysis machine. Therefore, in conjunction with the valves V1 to V4 that switch the inflow and outflow of the pump chambers 6 and 6', a pump flow passing through the box can be generated. Here, the pump chamber can be connected to all interfaces of the box via the corresponding valve switching.

[0073] The pump chambers 6 and 6 ′ can be fluidically coupled to one another via valves V1 to V4 , which can lead to a pressure balance in the operating pump chambers and thus to the problem of the distortion of the measured value of the delivery pressure described above.

[0074] Furthermore, in the example described, a heating region 7 is integrated into the cassette. In this region, the cassette is in contact with a heating element of the dialysis machine, which heats the dialysate flowing through this region of the cassette. The heating region 7 has a channel for the dialysate, which extends spirally over the heating region 7. The channel is formed by a web of a hard part, which is covered by the flexible film 2. The heating region can be arranged on both sides of the cassette or can also be arranged only on one side of the cassette.

[0075] In addition, the following embodiment of the box is possible, in which the heating element is integrated into the box. In particular, the electric heating element, such as a heating coil, can be injected into the hard part of the box. It is thus possible to discard the heating element on the machine side and integrate the flow heating device into the box. In this case, electrical contacts for connecting the electric heating element are provided at the box. In addition, the box has sensor areas 8 and 9, through which, for example, the temperature sensor of the dialysis machine can be coupled to the box.

[0076] Box Figure 2 The second embodiment shown in the figure also has a fluid path that can be opened and closed via valve areas, which are also numbered consecutively from V1 to V16 here. In addition, the box has interfaces for connecting to other components of the fluid system. Here, an interface 3 for connecting to the outflow part and an interface 4 for connecting to the connector leading to the patient are provided. In addition, an interface 5 for connecting to a dialysate container is provided. In the embodiment described, each of the pump chambers 6 and 6' is associated with a pressure sensor 10, by means of which the delivery pressure of the corresponding pump chamber can be measured.

[0077] and Figure 1 The boxes in Figure 2 The cassette shown in FIG. 1 has a further interface 11 for connecting a heating bag. In order to heat the liquid from the dialysate container, the liquid can be pumped into the heating bag via the interface 11. The heating bag is located on a heating element so that the liquid in the heating bag can be heated. The liquid is then pumped from the heating bag to the patient.

[0078] In order to achieve a continuous volume flow of dialysate, the dialysate is delivered alternately by means of the pump chambers 6 and 6'. For example, while the pump chamber 6 extracts (suctions) fluid from the patient, the pump chamber 6' delivers the balancing volume into the discharge line and is then recoupled to the connecting line to the patient in a conventional manner, whereby the second pump can continue the next suction stroke without time delay. The process is repeated until the prescribed treatment volume is extracted from the patient.

[0079] As described above, this direct recoupling of the emptied pump chamber 6' causes measurable fluid displacements and pressure pulses, which can distort the measurement result of the pressure sensor 10. The movement of the pump actuator of the dialysis machine, which presses the membrane 2 into the pump chambers 6 and 6' or pulls it out of the pump chamber again, causes volume displacements in the cassette interior, which can be detected via the pressure sensor 10. Such movements of the pump actuator of the dialysis machine can therefore bring about disruptive pump effects, which, in addition to physical effects, can distort the pressure measurement by means of the pressure sensor 10.

[0080] Examples of pump effects include friction, pump play and breakaway torque. Examples of physical effects include the mass inertia of the dialysis solution, the flow resistance of the hose or potential patient line constrictions. All or at least a certain number of these interfering effects can be avoided or reduced by means of the invention.

[0081] Figure 3 The method steps are described which are respectively carried out by a first pump (left side) and a second pump (right side) within the scope of an embodiment of the present invention. Figure 3 In FIG. 1 , the time axis extends from top to bottom. The delay time period between the valve switching time point of the first pump and the valve switching time point of the second pump is Figure 3 It is therefore already clear at first glance that the valve switching times of the first pump and the second pump are separated in time from one another.

[0082] In a first step S1, a valve is switched in the first pump in order to connect the pump to the patient inlet. Subsequently, in step S2, the first pump delivers the solution from the patient. After the solution has been delivered from the patient by the first pump in step S2, the air-free nature of the solution is checked in step S3. Subsequently, in step S4, the valve of the first pump is switched so that the first pump is connected to the drainage or outflow and in a subsequent step, the solution is delivered to the outflow.

[0083] In step S5, the second pump first outputs the solution from the patient. Subsequently, in step S6, the solution is checked to be air-free. In step S7, the valve of the second pump is switched so that the second pump is connected to the drainage part or the outflow part, and in the subsequent step S8, the solution is delivered to the outflow part.

[0084] As in Figure 3 As can be seen in FIG. 1 , the valve switching time point of the first pump in step S1 and the valve switching time point of the second pump in step S7 are staggered in time and thus separated from each other. Therefore, the valve switching time point of the second pump in step S7 is delayed by a delay time period Δt relative to the valve switching time point of the first pump in step S1.

[0085] In step S9, a valve is switched in the second pump to connect the pump to the patient's inlet. Subsequently, in step S10, the second pump delivers the solution from the patient. Figure 3 As shown in FIG. 1 , the valve switching time of the first pump in step S4 and the valve switching time of the second pump in step S9 are also offset in time and thus separated from each other in time.

[0086] Figure 4 An example of an optimization algorithm according to a decision tree is shown. Such an optimization algorithm can be implemented, for example, by a control device of the device according to the invention. According to the decision algorithm shown, it can be logically determined for a specific time point whether the second pump should be coupled at said time point. First, the algorithm starts at startup.

[0087] Then in diamond #1 it is checked whether the last pump stroke is present. If no more dialysate volume is contained in the patient, such a last pump stroke can be present, for example, at the end of a phase, for example, an outflow phase. If the last pump stroke is present, the second pump is not coupled (for example, because no further dialysate should be delivered in the outflow phase) and the algorithm ends. If the last pump stroke is not present, the optimization algorithm proceeds to diamond #2.

[0088] In diamond #2, it is checked whether a specific type of therapy is present, such as a pediatric therapy. If, for example, a pediatric therapy is present, then the second pump is not coupled and the algorithm ends. If there is no pediatric therapy, then the optimization algorithm proceeds to diamond #3.

[0089] In diamond #3, it is checked whether the pump that is delivering, for example the first pump, has already completed its movement. If this check shows that the pump has already completed its movement, the second pump can be coupled. The check according to diamond #3 has the following advantage: If the stroke of the first pump that is delivering ends faster than expected, the second pump can be coupled directly as soon as the movement of the first pump has ended. Unnecessary time delays are thus avoided and the switch-on time of the second pump is individually adapted to the given conditions. If the check in diamond #3 shows that the pump that is delivering has not yet completed its movement, the optimization algorithm proceeds to diamond #4.

[0090] In diamond #4, it is checked whether the pump speed of the conveying pump is high or is above a certain limit value, from which the valve switching influences the pressure measurement only to a negligible extent. Such a limit value can be, for example, 100 ml / min. If the pump speed of the conveying pump is above the certain limit value, the second pump is coupled. If the pump speed of the conveying pump is below the certain limit value, the optimization algorithm proceeds to diamond #5.

[0091] In diamond #5, it is checked whether the pump that delivers, for example the first pump, has finished its movement. If the check shows that the pump has finished its movement, the second pump can be coupled. Therefore, in this step, the switching on of the second pump is waited for until it is expected that the switching on of the second pump will no longer have a disruptive effect on the operation of the first pump.

[0092] If the check in diamond #5 concludes that the pump has not yet completed its movement, then the check in diamond #5 is repeated until the pump has completed its movement.

Claims

1. A device for dialysis treatment, in particular for peritoneal dialysis, comprising: a discontinuous first pump and a discontinuous second pump which can be switched by means of at least two valves; and a control device for generating a continuous volume flow of dialysis fluid, It is characterized in that The control device is designed to perform at least one of the following steps: a) suspending at least one pressure measurement during the switching time of at least one of the valves; b) performing a computational compensation of a portion of the result of the pressure measurement that is based on the device characteristic during the switching time of at least one of the valves; c) postponing the valve switching time of the second pump so that the valve switching time of the second pump does not coincide with the valve switching time of the first pump; and d) adaptively delaying the valve switching time of the second pump so that the valve switching time is inconsistent with the valve switching time of the first pump, wherein in the control device, an optimization algorithm is preferably used to determine the following time point: the valve switching time of the second pump is delayed to the said time point.

2. The device according to claim 1, It is characterized in that The control device is designed to carry out at least one of the steps in an inflow phase of a peritoneal dialysis treatment and / or in an outflow phase of a peritoneal dialysis treatment.

3. The device according to claim 1 or 2, It is characterized in that The control device is designed to open the valve that fluidically connects the first pump to the second pump only when the second pump has completely completed its last pump stroke and / or is not operating.

4. The device according to any one of the preceding claims, It is characterized in that The first pump and the second pump each interact with a pump chamber formed in the disposable article in order to convey the fluid, and at least two of the valves are preferably each a component of the disposable article.

5. The device according to any one of the preceding claims, It is characterized in that During the computational compensation, pressure profiles from a database accompanying the system properties, in particular accompanying valve switching, are used in order to thereby identify and compensate for system-specific components of the result of the pressure measurement during the switching time of at least one of the valves.

6. The device according to any one of the preceding claims, It is characterized in that The control device is designed to use the optimization algorithm to determine or precalculate a time point to which the valve switching time point of the second pump is postponed, wherein the optimization algorithm takes into account at a given time point at least one of the following parameters: the flow rate of the first pump and / or the second pump, preferably the flow rate of the pump of the first pump and the second pump that is operating at the time point; the last delivered pump chamber volume of the first pump and / or the second pump, preferably the flow rate of the pump of the first pump and the second pump that is operating at the time point; the volume and type of treatment being performed on the patient.

7. The device according to claim 6, It is characterized in that The optimization algorithm is designed to minimize a time delay between a valve switching time of the second pump for starting a pump stroke of the second pump and a valve switching time of the first pump at the end of a pump stroke of the first pump.

8. The device according to claim 1, It is characterized in that The step c) includes: starting from the valve switching time point of the first pump, delaying the valve switching time point of the second pump by a fixed delay time period, so that the valve switching time point of the second pump is inconsistent with the valve switching time point of the first pump.

9. The device according to any one of the preceding claims, It is characterized in that The step d) includes: starting from the valve switching time point of the first pump, delaying the valve switching time point of the second pump by the following delay time period, wherein the delay time period is variable and preferably determined individually by the optimization algorithm for each valve switching process, so that the valve switching time point of the second pump is inconsistent with the valve switching time point of the first pump.

10. A method for generating a continuous volume flow of a dialysate by means of a device for extracorporeal blood treatment, preferably a device for extracorporeal blood treatment according to any one of claims 1 to 9, the device having a discontinuous first pump and a discontinuous second pump that can be switched by means of at least two valves, wherein the method comprises at least one of the following steps: a) pausing at least one pressure measurement during the switching time of at least one of the valves; b) computationally compensating a portion of the result of the pressure measurement that is based on device characteristics during the switching time of at least one of the valves; c) postponing the valve switching time of the second pump so that the valve switching time of the second pump is inconsistent with the valve switching time of the first pump; and d) adaptively postponing the valve switching time of the second pump so that the valve switching time is inconsistent with the valve switching time of the first pump, wherein an optimization algorithm is preferably used to determine the following time point, to which the valve switching time of the second pump is postponed.

11. The method according to claim 10, It is characterized in that At least one of the steps is performed during an inflow phase of a peritoneal dialysis treatment and / or during an outflow phase of a peritoneal dialysis treatment.

12. The method according to claim 10 or 11, It is characterized in that The valve fluidly connecting the first pump to the second pump is opened only when the second pump has completely completed the last pump stroke and / or is not operating.

13. The method according to any one of claims 10 to 12, It is characterized in that During the computational compensation, pressure profiles from a database associated with the system properties, in particular associated with valve switching, are used in order to thereby identify and compensate for system-specific components of the results of the pressure measurement during the switching time of at least one of the valves.

14. The method according to any one of claims 10 to 13, It is characterized in that The optimization algorithm is used to determine or precalculate the following time point, to which the valve switching time point of the second pump is postponed, wherein the optimization algorithm takes into account at least one of the following parameters at a given time point: the flow rate of the first pump and / or the second pump, preferably the flow rate of the pump of the first pump and the second pump that is operating at the time point; the last delivered pump chamber volume of the first pump and / or the second pump, preferably the flow rate of the pump of the first pump and the second pump that is operating at the time point; the volume and type of treatment being performed in the patient.

15. The method according to claim 14, It is characterized in that The optimization algorithm is designed to minimize a time delay between a valve switching time of the second pump for starting a pump stroke of the second pump and a valve switching time of the first pump at the end of a pump stroke of the first pump.

16. The method according to any one of claims 10 to 14, It is characterized in that The step c) includes: starting from the valve switching time point of the first pump, delaying the valve switching time point of the second pump by a fixed delay time period, so that the valve switching time point of the second pump is inconsistent with the valve switching time point of the first pump.

17. The method according to any one of claims 10 to 15, It is characterized in that The step d) includes: starting from the valve switching time point of the first pump, postponing the valve switching time point of the second pump by the following delay time period, wherein the delay time period is variable and preferably determined individually by the optimization algorithm for each valve switching process, so that the valve switching time point of the second pump is inconsistent with the valve switching time point of the first pump.

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