Control unit for controlling a blood treatment device, control unit, user interface and blood treatment device

Abstract

Control device (20), programmed to execute a method for controlling or regulating a device (4) for the extracorporeal treatment of blood in an extracorporeal blood circuit (1) by adding citrate for the purpose of anticoagulation, wherein the device (4) comprises an addition device (12) for adding a calcium solution to the extracorporeal blood circuit (1), or for controlling the addition device (12), the procedure includes the following steps: - Outputting a signal to the addition device (12) to change a setting of the addition device (12), wherein the setting corresponds to or causes an addition of calcium, a calcium dosage or concentration or amount or rate; characterized by the steps - Determining the signal taking into account the calcium content or calcium concentration of a substitution solution used in extracorporeal treatment of the blood; and - Determining the range of values ​​of a permissible or approved setting range for the calcium introduced or to be introduced into the extracorporeal blood circulation (1) by means of the addition device (12), in particular its quantity, concentration or dosage, under - Setting a lower limit value for the adjustment range that is considered the smallest permissible value.

Description

[0001] The present invention relates to a control device for carrying out a method for controlling or regulating a device for the extracorporeal treatment of blood according to claim 1. It further relates to a user interface according to claim 8, and to a device for the extracorporeal treatment of blood according to claim 10.

[0002] In certain extracorporeal blood treatments, coagulation prophylaxis is used to prevent coagulation of the extracorporeally drawn blood. In a known method for this purpose, the tendency of the extracorporeally flowing blood to coagulate is reduced by first adding citrate to the blood. The addition of citrate increases the permeability of calcium through the membrane of the filter used. This, along with the use of calcium-free solutions during the blood treatment, leads to a loss of calcium from the blood. After the blood has been treated, calcium is added to the blood in the form of a calcium-containing solution before it is returned to the patient's body. Methods and devices for determining the amount or concentration of calcium required to achieve this effect are known in practice.

[0003] US patent 2007 / 0066928 A1 describes the automation and optimization of CRRT treatment using regional citrate coagulation.

[0004] From WO 2010 / 029417 A2, a device and method for extracorporeal blood treatment are known.

[0005] An object of the present invention is to propose a control device for carrying out a further method for controlling or regulating a device for the extracorporeal treatment of blood by adding citrate (hereinafter also abbreviated as Ci) and calcium (hereinafter also abbreviated as Ca). Furthermore, a corresponding user interface and a device are to be specified.

[0006] The problem according to the invention is solved by a control device with the features according to claim 1, a user interface with the features according to claim 8 and by a device with the features according to claim 10.

[0007] According to the present invention, a control device is proposed for carrying out a method for controlling or regulating a device used for the extracorporeal treatment of blood, wherein the blood is treated in an extracorporeal blood circulation with the addition of citrate for anticoagulation or coagulation prophylaxis. The regulated or controlled device also includes an addition device for adding a calcium solution to the extracorporeal blood circulation. Alternatively, the method according to the invention serves to control or regulate such an addition device.

[0008] The method involves detecting and / or outputting a signal to the delivery device to change a setting of the delivery device by means of which calcium is added to the extracorporeal blood flow. The setting corresponds to or causes the delivery of calcium, a calcium dosage, concentration, amount, or rate.

[0009] The procedure further includes setting or changing the signal taking into account a calcium content or calcium concentration of a substitution solution used in extracorporeal treatment of the blood.

[0010] Furthermore, the procedure includes determining the range of values ​​of a permissible or approved setting range for the calcium introduced or to be introduced into the extracorporeal blood circulation by means of the addition device, in particular its quantity, concentration or dosage.

[0011] The control device according to the invention is provided and / or programmed to execute the method.

[0012] The user interface according to the invention includes a control device according to the invention and / or is functionally connected to such a device. The user interface according to the invention includes an input device. The input device is provided for specifying or entering (in the sense of communicating) a calcium dosage, quantity, or concentration by the user of the user interface, the addition of which is to be initiated or effected by means of the control device.

[0013] The input device may be a button or keyboard, a slider, a touchscreen or any other display or means prepared for data input, a computer mouse, or the like.

[0014] The device according to the invention is intended for the extracorporeal treatment of blood. It is also designed and intended for carrying out or performing the method, and / or comprises at least one control device according to the invention, and / or a device according to the invention for adding a calcium solution into the extracorporeal blood circulation, and / or a user interface according to the invention.

[0015] All the advantages achievable with the method disclosed herein can be achieved without diminishment in certain embodiments of the invention with each of the objects according to the invention.

[0016] Embodiments according to the invention may have one or more of the features listed below. Embodiments according to the invention are also the subject of the dependent claims.

[0017] In all the following explanations, the use of the expression "may be" or "may have" etc. is to be understood as synonymous with "is preferably" or "has preferably" etc. and is intended to explain certain embodiments of the invention.

[0018] In certain embodiments of the invention, the addition device for adding a calcium solution into the extracorporeal blood circulation is a pump, in particular a calcium pump.

[0019] In certain embodiments of the invention, the addition device for adding a calcium solution is provided exclusively for adding calcium solution to achieve calcium balance or calcium compensation.

[0020] In certain embodiments of the invention, the determination of the permissible or approved setting range for the calcium introduced or to be introduced into the extracorporeal bloodstream by means of the delivery device, in particular its quantity, concentration, or dosage, is performed anew with each setting or change. In some embodiments of the invention, this determination is performed multiple times during a blood treatment, as necessary. The value range or its lowest value is thus determined dynamically in some embodiments of the invention.

[0021] In some embodiments of the invention, "controlling" is to be understood as "regulating." Both terms are equally encompassed by the present invention wherever feasible to a person skilled in the art. Therefore, when referring to a control device or a control mechanism, it may also mean a regulation device or a rule, provided this is technically appropriate.

[0022] In certain embodiments of the invention, the method comprises setting a lower value considered to be the smallest permissible value - hereinafter also referred to in part as "lower threshold" or "minimal calcium dose" and therefore to be understood as synonyms whenever this seems sensible to the person skilled in the art - of the adjustment range, in particular to a value equal to or greater than zero.

[0023] In some embodiments of the invention, the method comprises the detection – particularly automatically – of a blood treatment mode set or running on the device for extracorporeal blood treatment. If it is detected that a blood treatment mode is set or running in which substitution with a substitute takes place, the required calcium compensation can advantageously be calculated automatically using the method of the invention. In particular, the calcium content of the substitute used can advantageously be taken into account automatically.

[0024] In some embodiments of the invention, the method includes determining the lowest permissible threshold value of the adjustment range. Since calcium substitution or administration already occurs via the substitute when using a calcium-containing substitution solution, the calcium dosage due to the amount of calcium applied via the substitution solution is already greater than 0.0 mmol / l. Assuming a step size of 0.1 mmol / l, the minimum calcium dose is already 0.1 mmol / l.

[0025] In some embodiments of the invention, the method includes determining the lowest permissible threshold value of the value range of the setting range according to Ca_Dosis_min=[Ca]_Sub*Q_Sub+[Ca]_Lsg*Q_Ca_minQ_Fil+Q_Ca_min

[0026] In formula (1) the following applies: Ca_Dose_min is the minimum calcium dose, or the lowest permissible value or lower threshold of the range; [Ca]_Sub is the calcium concentration of the substitute; Q_Sub is the substitute flow rate; [Ca]_Lsg is the calcium concentration of the calcium solution; Q_Ca_min is the minimum calcium flow rate; and Q_Fil is the filtrate flow rate. For the sake of simplicity in presenting formula (1), the filtrate flow rate Q_Fil is defined here as the flow rate of the filtrate out of the filter, reduced by the portion of the filtrate that compensates for the volume infused with the calcium flow rate (Q_Ca). In reality, in addition to the filtrate flow rate defined here, the flow rate through the filtrate line also compensates for the volume infused with the calcium flow rate (Q_Ca).

[0027] The filtrate flow rate (Q_Fil) defined in this way corresponds, in certain embodiments of the invention, to the sum of the substitute flow rate (Q_Sub), dialysate flow rate (Q_Dia), citrate flow rate (Q_Ci), net ultrafiltration flow rate (Q_UF), and heparin flow rate (Q_Hep). However, in other embodiments of the invention, the filtrate flow rate can correspond to the sum of two or more of the flows mentioned in the preceding sentence, in any combination. In some embodiments of the invention, the flows that sum to produce the filtrate flow rate are not limited to the flows mentioned here. For example, in a treatment device equipped with a phosphate pump, a phosphate flow rate or a corresponding compensation flow rate can also be included in the sum that constitutes the filtrate flow rate.

[0028] In some embodiments of the invention, the filtrate flow rate is the flow rate of the liquid that is formed in the treatment device. This flow rate is optionally reduced by the portion that compensates for the volume inundated by the calcium flow.

[0029] The aforementioned fluxes – and also a calcium flux – can each be calculated, set, or determined fluxes or rates at the respective pumps.

[0030] If the minimum possible calcium flow (Q_Ca) corresponds to a stop or complete cessation of calcium flow, then Q_Ca = 0. Formula (1) can therefore also be expressed as formula (1') in the corresponding embodiments of the invention: Ca_Dosis_min=[Ca]_Sub*Q_SubQ_Fil be used.

[0031] Since the heparin flow (Q_Hep) is often very low, Q_Hep can be neglected or determined to be zero in certain embodiments of the invention and then does not contribute to the filtrate flow (Q_Fil) or is not included in it.

[0032] In certain embodiments of the invention, the value calculated using formula (1) or (1') is rounded up to the nearest tenth of a mmol / l. This can advantageously and possibly significantly reduce the implementation and / or control effort.

[0033] Formula (1) can be derived from the consideration that when determining the calcium dose for calcium compensation, the total calcium administration must be taken into account, and that the minimum possible calcium dose is reached when the minimum possible calcium flow is zero, see formula (2): Ca_Dose=[Ca]_Sub*Q_Sub+[Ca]_Lsg*Q_CaQ_Fil+Q_Ca

[0034] The denominator of formula (2) indicates the flow of the filtrate out of the filter and is higher by the desired water removal (Q_UF) than the sum of all flows (in particular of substitute, dialysate, citrate and heparin (each flow and in particular a heparin flow is only considered if the administration of the corresponding fluid or substance such as heparin actually takes place here)) that are applied towards the extracorporeal blood circulation, including the calcium flow.

[0035] Formula (1) is clearly derived from formula (2) in the case where the calcium flow Q_Ca is set equal to, or assumed to be equal to, the minimum possible calcium flow Q_Ca_min. In this case, formula (1) yields a limit value in the sense of a minimum or minimum possible dose. This is obtained when the calcium supply from a calcium source, used for the purpose of calcium balancing, is minimized.

[0036] A minimized calcium flow or a minimized calcium supply is understood here to mean the flow generated by a calcium pump when the calcium pump is set to the lowest possible delivery setting in its normal operation. At this setting, where the pump is not completely switched off and the flow it generates is consequently not zero, the resulting calcium flow is also referred to, in connection with the present invention, as the "minimum possible" calcium flow Q_Ca_min.

[0037] From the above formulas, the following formula (3) results for the flow rate Q_Ca of the calcium solution, which usually has the dimension [ml / h]: Q_Ca=Ca_Dose*Q_Fil−[Ca]_Sub*Q_Sub[Ca]_Lsg−Ca_Dose

[0038] According to the invention, the calcium flow Q_Ca can be used to control or regulate the calcium pump, as is provided in certain embodiments of the invention.

[0039] A calcium dose, or Ca dose, is understood to be the amount of calcium per unit volume of fluid. In some embodiments of the invention, a calcium dose, or Ca dose, is understood to be the ratio of calcium (in millimoles [mmol]) to the filtrate or effluent (in liters [1]). The terms filtrate, effluent, and effluent are used synonymously here. They all refer to the mixture of used dialysate and the fluid filtered through the filter membrane, which is discarded during or after treatment.

[0040] In some embodiments of the invention, the term "filtrate" refers to the sum of all liquids discarded during or after treatment (e.g., the entire effluent). In some embodiments, the calcium flow or a corresponding compensatory flow is expressly excluded, while in others it is. In certain embodiments, the heparin flow or a corresponding compensatory flow is expressly excluded, while in others it is.

[0041] In some embodiments of the invention, a calcium dose is understood to be the total amount of calcium infused into the extracorporeal blood circulation (i.e., the sum of the calcium from the substitution solution and the calcium from the calcium solution added by means of the addition device for the purpose of calcium balancing) in relation to the amount of filtrate formed (or the volume pumped by the filtrate pump).

[0042] In some embodiments of the invention, the method explicitly allows the user or operator of the device or the adding device to adjust the calcium dosage, amount or concentration only within the range of the adjustment range and / or not below the lowest permissible value or threshold value.

[0043] This can be ensured by not displaying and therefore not making selectable values ​​other than those permitted. Furthermore, this can be ensured by issuing warnings, alarms, or error messages should the user enter or attempt to enter an invalid value.

[0044] In this way, a harmful attitude, whether conscious or unconscious, can be advantageously avoided by the user.

[0045] In some embodiments, the method according to the invention includes issuing a notification when a container for the substitute used has been or is about to be changed, or when a change in the composition or calcium content or concentration of the substitute used has occurred, been detected or is planned.

[0046] This advantageously ensures that variations in calcium concentration between different substitution solutions – which may even be sourced from different manufacturers – are reliably accommodated. In certain configurations, a notification that appears when the container for the substitute solution is changed allows for manual or – after entering specific information about the substitution solution now being used – automatic adjustment of the calcium dose added by the dosing device.

[0047] In certain embodiments of the invention, an adjustment range for the calcium concentration of the substitution solution used comprises values ​​between 1.00 mmol / l and 2.00 mmol / l. Other value ranges are also covered by the invention. In some embodiments, the adjustment range can be adjusted in increments of 0.25 mmol / l. A default or basic setting for the substitution solution may be 1.5 mmol / l, if provided. Each default value can be changed by the user and / or automatically.

[0048] In some embodiments of the invention, the method includes displaying a message that appears during or in connection with changing or replacing the substitution bag, indicating to the user the required calcium concentration of the substitution solution. The message can be displayed on a monitor. It can also be integrated into a message indicating that the substitution bag needs to be changed. Such a message can advantageously contribute to treatment safety.

[0049] In certain embodiments of the invention, the method comprises adjusting the minimum permissible value of the value range or lower threshold value due to changes in the delivery rate of the blood pump and / or the dialysate pump or due to changes in the flows resulting from their activities.

[0050] In certain embodiments of the invention, the adjustment of the lower permissible value or threshold is advantageously carried out automatically, i.e., on the control side or on the machine side, and without user intervention. In this way, user intervention that would otherwise be unnecessary can be advantageously avoided, with the benefits known herein.

[0051] In certain embodiments of the invention, adjusting the lower value or threshold considered to be the smallest permissible value is in some cases an increase in the value or threshold.

[0052] In some embodiments of the invention, the method comprises a permanent or temporary reduction of the rate or flow rate at which the substitute or substitute solution is supplied to the extracorporeal bloodstream. When reducing the rate or determining the extent of the reduction, any existing, expected, or planned reduction—permanent or temporary—in the blood flow within the extracorporeal bloodstream is taken into account, for example, mathematically. This can advantageously help to avoid excessive hemoconcentration of the blood at the filter outlet. High hemoconcentration can increase the risk of coagulation in the extracorporeal bloodstream.

[0053] In some embodiments of the invention, the method includes allowing the user to lower the calcium dose added by the dosing device below the previously deemed minimum permissible value or below the previously deemed lower threshold of the adjustment range, if—or when—the minimum calcium dose resulting from a change in blood flow is lower than before the change. This advantageously makes it possible to relax or abandon a restriction previously deemed necessary. The user—or the machine in the case of automatic adjustment—is then free to use this now-released or permissible adjustment option (for the first time or, if necessary, again).

[0054] In certain embodiments of the invention, a lower value or lower threshold previously considered to be the minimum permissible value is a value that was previously determined, calculated, set, or ascertained as such in a prior calculation or determination according to the inventive method. In some embodiments of the invention, the value "previously" is a preceding or the last value or threshold determined according to the invention.

[0055] In some of these embodiments, it may be possible to issue a corresponding notification to the user.

[0056] In certain embodiments of the invention, a notification, as used in various places herein, may be an optical or acoustic alarm, text in a display window or the like, as well as combinations thereof.

[0057] In certain embodiments of the invention, the user interface has a display which is provided and / or controlled to display the lowest permissible value or the lower threshold value.

[0058] In certain embodiments of the invention, it is provided that, in addition to or as an alternative to the lower permissible value, lower threshold, or minimum calcium dose, an upper permissible value, upper threshold, or maximum calcium dose is specified. What is stated herein regarding the lower permissible value, lower threshold, or minimum calcium dose also applies, according to the invention, to the upper permissible value, upper threshold, or maximum calcium dose and falls within the scope of the present invention, insofar as this is recognizable as meaningful and / or feasible to a person skilled in the art.

[0059] In some embodiments of the invention, the device is designed as a dialysis device, in particular as a hemodiafiltration device or hemofiltration device.

[0060] In certain embodiments of the invention, the device is designed as a dialysis device, which is designed and provided for blood treatment by means of both hemodiafiltration and hemofiltration and, if necessary, other treatment options.

[0061] For example, instead of hemofiltration under Ci-Ca anticoagulation (e.g., CVVHD: Continuous Veno-Venous Hemodialysis), which is already implemented in the machine, hemodiafiltration under Ci-Ca anticoagulation (e.g., CVVHDF: Continuous Veno-Venous Hemodiafiltration) can optionally be performed with a device according to the invention. The necessary adjustments to the device for one or the other of the two methods can be kept to a minimum, particularly when using a user interface according to the invention, such that selecting one method compared to the other does not require any significant change or adjustment for the user.

[0062] In certain embodiments of the invention, hemodiafiltration under Ci-Ca anticoagulation (e.g., CVVHDF) is performed with a substitution (e.g., using a "multiBic" solution from the applicant's company) in postdilution. The corresponding requirements for controls, lines, etc., are ensured or provided.

[0063] Certain embodiments of the invention, in addition to the advantages already mentioned elsewhere, have one or more of the advantages mentioned below.

[0064] In hemodiafiltration procedures, more fluid is removed from the blood than is clinically necessary for dehydration. This allows for the removal of a greater proportion of uremic toxins from the blood. The fluid balance is compensated for by introducing a substitute into the extracorporeal circulation. Since the substitution solution used contains or may contain calcium, the calcium contained in the substitution solution is advantageously taken into account during calcium compensation according to the invention.

[0065] In certain embodiments of the invention, the method advantageously allows for the resolution of the contradiction, or rather, the provision of a solution, that arises when calcium compensation also takes into account the calcium contained in hemofiltration or in a substitute, and furthermore, that in certain such constellations and parameter values, the calcium flow itself, or based purely on the mathematical formula used, would have to be set to a negative value. In these embodiments, the solution according to the invention consists of providing a technically sensible and feasible solution – contrary to what is required by calculation, but is not technically practical. This solution can consist of maintaining the calcium flow at a minimum value.

[0066] The present invention further offers, in some embodiments, a particularly user-friendly implementation of the method according to the invention. This advantage is also based on the fact that the user can work with familiar user interfaces of the treatment device used. The user interfaces in question differ only slightly from those already available to the user for another known method. The user can continue to work with the familiar appearance of the user interfaces.

[0067] The present invention is explained below by way of example with reference to the accompanying drawing, in which identical reference numerals denote identical or similar components. In the partially simplified figures, the following applies: Fig. Figure 1 shows a simplified schematic representation of a blood circulation system with an addition device for adding a calcium-containing substitute; Fig. Figure 2 shows possible adjustment ranges for calcium dosage with the aim of calcium balance, as well as the limits of the adjustment range; and Fig. Figure 3 shows a user interface according to the invention for carrying out the method according to the invention.

[0068] Fig. Figure 1 schematically shows a simplified blood circuit 1 with a dialysis filter or blood filter or filter 3 for performing extracorporeal blood treatment, in which blood coagulation is influenced by the administration of citrate calcium. The filter 3 is connected to a device 4 according to the invention for the extracorporeal treatment of blood, which is located in Fig. 1 is only indicated by dashed lines.

[0069] The blood circulation 1 comprises an arterial patient line (line 5) leading away from a patient P, with a blood pump 7. A citrate solution is dispensed into line 5 from a citrate solution source, here exemplified as a citrate bag 9. For example, 4% sodium citrate is supplied from the citrate solution source.

[0070] The blood circulation 1 further includes a venous patient line or line 11 leading to the patient P. An injection device, here designed as a calcium pump 12, is provided to supply calcium solution from a source in Fig. 1. For example, a calcium bag 13 is designed to deliver a calcium solution into line 11. A CaCl2 solution, for instance, is supplied from the calcium solution source. This solution can have a calcium concentration of 91 mmol / l.

[0071] Filter 3 is connected on the dialysate side to a dialysate source, e.g., a dialysate bag 15. Dialysate, e.g., a citrate-calcium (Ci-Ca) dialysate K2, is supplied to Filter 3 from the dialysate source. Filter 3 is also connected to an outlet 17.

[0072] Line 11 is further connected to a source of substitute, here in the form of a substitute bag 19. The bag 19 contains a calcium-containing substitute, which could, for example, be the product "multiBic" from Fresenius Medical Care Deutschland GmbH. For illustrative purposes only, bag 19—as an example of a source of substitute—is arranged for the addition of the substitute in post-dilution, i.e., at a point in the blood circuit 1 located downstream of filter 3 in the direction of blood flow.

[0073] The blood flow set by means of blood pump 7 can be adjusted to 100 ml / min. At a Fig. The pump (not shown) for pumping citrate solution from citrate bag 9 can be set to a flow rate of 180 ml / h. The addition device 12, configured here as a calcium pump, for pumping calcium solution from calcium bag 13 into the extracorporeal blood circulation 1 can be set to a flow rate of 45 ml / h. At a Fig. The pump (not shown) for pumping dialysate from dialysate bag 15 can be set to a flow rate of 1800 ml / h. At a [location / location] Fig. The pump (not shown) for pumping the substitute from the substitute bag 19 can be set to a flow rate of 1000 ml / h. The outflow can be approximately 3100 ml / h. Its size depends on the net ultrafiltration rate targeted by the physician.

[0074] Out of Fig. 1 shows that calcium is supplied to patient P from the calcium bag 13, the dialysate bag 15 and the substitution bag 19.

[0075] The supply of calcium or calcium solution from the calcium bag 13 by means of the calcium pump 12 is controlled or regulated by a control unit 20 of the device 4. A corresponding signal connection is indicated by a dash-dot line.

[0076] Fig. Figure 2 shows exemplary possible adjustment ranges for calcium dosage for the purpose of calcium balancing. Fig. Figure 2 further shows the limits of the adjustment range. The dimension of the dosage for calcium, in Fig. 2, referred to as calcium dose, is millimoles per liter [mmol / l]. The amount in the example of Fig. 2. The permissible or approved adjustment range for the dosage of calcium for calcium compensation extends over the value range which ranges from 0 to 3 mmol / l.

[0077] Setting a calcium dose within range 21 corresponds to substituting an amount of calcium that is less than the expected amount of calcium removed by the blood treatment. Setting this dose within this range could lead to undesirable calcium loss; therefore, in certain embodiments of the invention, setting such a dose may be accompanied by the display of a warning, a visual or audible alarm, or the like. Alternatively, attempting to set a calcium dose within range 21 may also indicate that less calcium than expected is passing from the blood through the membrane and being removed with the effluent. This may result from reduced membrane permeability. The user or the treatment device may be alerted to this possibility in certain embodiments of the invention.

[0078] Setting a calcium dose within the range of 23 would meet expectations and would not result in any notification to the user.

[0079] Setting a calcium dose within the range of 25 corresponds to calcium substitution exceeding the expected calcium removal via the effluent. In certain embodiments of the invention, a warning to the user regarding this is provided; in others, such a warning is omitted. It could also be pointed out that citrate accumulation may occur, as this is often associated with an increased need for calcium substitution.

[0080] Setting a calcium dose in the range of 27 would be considered too high and would not be permissible. Selecting such an impermissible value for calcium balancing using the device or pump would not be possible according to the invention. In some embodiments of the invention, if the user wishes to set a calcium dose in the range of 27, they may receive a notification advising them to check whether, under the given circumstances, another treatment option than the one set or implemented is more suitable and, if so, to adjust accordingly.

[0081] Furthermore, in some embodiments of the invention, parameters other than the calcium dose can be automatically adjusted, which can lead to a balanced calcium level. A list of automatically permissible changes can be stored. If adjustments are necessary or even carried out automatically, certain embodiments provide for informing the user accordingly.

[0082] Fig. Figure 3 shows a user interface 31 according to the invention for carrying out the method disclosed herein, which is not part of the invention.

[0083] On the left side of the user interface, 31 readings for arterial pressure (reference symbol 33), venous pressure (reference symbol 35), and transmembrane pressure (reference symbol 37) are displayed, each given in mmHg. The corresponding values ​​can be read both as numerical values ​​and as variable markings on scales 39.

[0084] The user interface 31 also features a display 41 of the currently set or measured blood flow, a display of the ultrafiltration rate 43, an indication 45 of whether continuous heparin administration is taking place (here with 0 for OFF), and an indication 47 of whether heparin administration is taking place via bolus (here with B for "bolus set").

[0085] The user interface 31 also features setting options 49 for a level of the venous bladder catcher and control interface 51 for displaying or controlling further treatment data or options.

[0086] In addition, the user interface 31 includes a display 53 for showing the set dialysate flow rate (corresponding to the dialysate rate), a display 55 for showing the set citrate flow rate in relation to the blood flow, and a display 57 for showing the set calcium flow rate in relation to the filtrate flow rate. In certain embodiments of the invention, all or some of the aforementioned and subsequently mentioned displays can also be used to change the set flow rates. They can be adjusted by touching the corresponding display areas.

[0087] The user interface 31 does not differ in the above description from a previously known user interface, such as can be used for another treatment option such as CVVHD (Continuous Veno-Venous Hemodialysis) in combination with citrate calcium anticoagulation.

[0088] However, the new or added display is 59, which shows the substitution flow rate. User interface 31 now also includes the information relevant for performing a procedure known as CVVHDF (Continuous Veno-Venous Hemodiafiltration) combined with citrate-calcium anticoagulation, as shown in the upper left corner of user interface 31.

[0089] The in Fig. The user interface 31 shown in Figure 3 is thus a further development of a user interface such as that which can be used in CVVHD. The user interface 31 according to the invention therefore differs advantageously only slightly from a user interface that the user is already familiar with from another blood treatment option. In certain embodiments of the invention, it can thus be easily adapted from a display for CVVHD to a display for CVVHDF and vice versa. It may suffice to offer a few more or fewer displays and / or setting options, depending on which of the aforementioned treatment options is to be pursued.This has the advantage that the user can use a user interface already familiar from one treatment option, with only minor modifications, when performing another treatment option or procedure. This avoids user confusion and eliminates the need for the user to be familiar with a multitude of user interfaces.

[0090] Should the user encounter an impossibility of achieving a desired calcium dosage value using the calcium pump, for example, if the calculated calcium flow from the calcium pump results in a negative value, then in certain embodiments of the invention, the calcium dosage is set to zero, to the minimum adjustable value, to a lower threshold value, or to a predetermined default value. In some embodiments of the invention, the minimum adjustable value is rounded up to the nearest 0.1 mmol / l. It can be calculated, for example, according to formula (1) or (1') given above, or in another suitable manner.

[0091] Such a technical impossibility of calculating the required calcium dose (e.g., a negative value) can be addressed, for example, by preventing the user from entering the desired but practically unfeasible calcium dose. For instance, the display computer, or any other suitable device, can be programmed to only offer the user sensible and / or technically feasible dosages. If the user nevertheless enters technically impossible or at least impermissible values ​​for the calcium dosage using the calcium pump—which may initially be possible in certain embodiments of the invention but not from the outset in others—a notification can preferably be provided to inform the user of the impossibility.

[0092] In certain embodiments of the invention, a notification is always given to the user whenever a machine-based, i.e., automatically adjusted, calcium dose setting deviates from the setting the user has requested and attempted to enter. This can help the user understand the device's behavior.

[0093] In some embodiments of the invention, the calcium dose can be automatically set to zero, to a minimum value, or to the calculated value (e.g., according to formula (1) or (1')) if, with or without user intervention, parameters other than the calcium dose—such as the dialysate flow or the substitution flow—change and affect the calculated calcium flow. The user can be informed of this by a notification, alarm, text message, etc.

[0094] An exception to the aforementioned procedure is provided in some embodiments of the invention when, after reaching the target balance (i.e., a target for the cumulative removal of water from the blood), ultrafiltration stops or ends, and the machine therefore enters a changed state (with respect to parameter values, flows, and the like). In certain embodiments of the invention, this does not require an adjustment of the calcium dose. Even in this situation, the user can be informed by a notification, alarm, text field, etc.

[0095] In certain embodiments of the invention, it is provided that, prior to an automatic change of parameter values, e.g., for the calcium pump, the applicable settings for any adjustable parameters of the device or the apparatus according to the invention (calcium dose and others) are automatically saved by the device or the apparatus according to the invention. Using the saved values, the machine parameters can be reset to their previous settings—automatically or at the user's request—at least when the previous settings are technically and medically appropriate, feasible, and desired. The user may receive a notification that, due to certain changes, previous values ​​can now be set again. Examples of such settings and parameters include, but are not limited to, the calcium dose, blood flow, dialysate flow, substitution flow, and others.

[0096] In some embodiments of the invention, a marker set in a previous treatment can be initialized as deleted at the start of the treatment. This marker is, for example, always set when the calcium dose has been automatically increased. The marker can be set when the user enters a calcium dose. Setting the marker at least temporarily saves the previously valid calcium dose value. If the marker is set and, after changing another parameter (optionally excluding the automatic reduction of the ultrafiltration rate to zero upon reaching the target balance), a reduction in the calcium dose is possible, or an increase in the calcium dose is necessary or advisable, the user can be notified that they can now reduce the calcium dose. The marker can then be deleted. Alternatively, such an adjustment can also be made automatically.

[0097] In some embodiments of the invention, the selection of the calcium dose is limited to a countably finite number of dose levels. In these embodiments, it is not, or not in every case, intended to set or control the lowest possible calcium dose, as calculated, for example, using formula (1) or (1'). In these configurations, for example, 0.1 mmol / l or 0.2 mmol / l can be provided as the adjustment range or adjustment steps, which has proven advantageous. Therefore, in some embodiments of the invention, a step size of 0.1 mmol / l or 0.2 mmol / l is provided for the available adjustment steps. Limiting the possible adjustment by or to at least 0.1 mmol / l or 0.2 mmol / l in each case advantageously allows for less complex preparation of the hardware used in the treatment, in particular the dosing device by which the calcium compensation is carried out, and its control system.Furthermore, this allows for a user interface design where even the smallest adjustment increments enable individualization of the treatment, while simultaneously avoiding the display of superfluous information by foregoing the greater precision of the display that would be required for smaller adjustment increments. This advantageously enhances the clarity of the user interface.

[0098] The following are three situations that will help to better understand the procedure. Situation 1

[0099] In an initial configuration of the device according to the invention, the following applies: Blutfluss 100 ml / min Substituatfluss (Q_Sub) 1000 ml / h Dialysatfluss (Q_Dia) 1800 ml / h Citratdosis 4 mmol / l Calciumdosis 1,7 mmol / l Netto-Ultrafiltratrate (Q_UF) 100 ml / h

[0100] The internally calculated flows are 176.47 ml / h for citrate and 37.95 ml / h for calcium.

[0101] Situation 1 reflects a normal operating condition.

[0102] If the user reduces the calcium dose to, for example, 1.2 mmol / l, the calcium flow rate changes to 22.18 ml / h, while all other values ​​remain unchanged. A note to the user stating "low calcium dose" may be appropriate – the filter may have lost its effectiveness.

[0103] If the calcium dose is reduced to 0.5 mmol / l, the calcium flow rate drops to 0.38 ml / h, while all other values ​​remain unchanged. A notification to the user stating "lower limit for calcium dose reached" may be advisable.

[0104] However, if the calcium dose is reduced to 0.4 mmol / l, the calcium flow would theoretically have to be lowered to -2.70 ml / h to achieve correct calcium balance while all other values ​​remain unchanged. Such a setting is clearly pointless and is therefore neither offered nor permitted. Situation 2

[0105] In another initial configuration of the device according to the invention, the following applies: Blutfluss 100 ml / min Substituatfluss 1000 ml / h Dialysatfluss 1800 ml / h Citratdosis 4 mmol / l Calciumdosis 0,7 mmol / l Netto-Ultrafiltratrate 100 ml / h

[0106] The internally calculated flow rates are 176.47 ml / h for the citrate solution and 6.58 ml / h for the calcium solution.

[0107] The calcium dose is low, but still permissible due to the high dialysate flow rate. However, reducing the dialysate flow rate can lead to a limit for the calcium dose, as shown below.

[0108] If the user reduces the dialysate flow to, for example, 800 ml / h, the calculated calcium flow changes to -0.47 ml / h, while all other values ​​remain unchanged. An automatic increase of the calcium dose to the lowest possible value is indicated here, possibly with a notification to the user.

[0109] After the calcium dose is automatically increased to, for example, 0.8 mmol / l, the calcium flow rate rises to 1.62 ml / h. This is an acceptable value. Situation 3

[0110] In yet another initial configuration of the device according to the invention, the following applies: Blutfluss 100 ml / min Substituatfluss 600 ml / h Dialysatfluss 1800 ml / h Citratdosis 4 mmol / l Calciumdosis 0,4 mmol / L Netto-Ultrafiltratrate 100 ml / h

[0111] The internally calculated flows of the citrate solution are 176.47 ml / h and of the calcium solution 1.71 ml / h.

[0112] The calcium dose is low, but still permissible due to the low substitution rate. However, increasing the substitution rate can lead to a limit on the calcium dose, as shown below.

[0113] If the user increases the substitution flow rate to, for example, 1000 ml / h, the calcium flow rate calculated as required to achieve calcium balance changes to -2.70 ml / h, with all other values ​​remaining unchanged. An automatic increase of the calcium dose to one of the lowest possible values ​​is also recommended here, possibly with notification to the user.

[0114] After the calcium dose was automatically increased to, for example, 0.5 mmol / l, the calcium flow rate rose to 0.38 ml / h, with all other values ​​remaining unchanged. This is an acceptable value.

Claims

[1] Control device (20), programmed to execute a method for controlling or regulating a device (4) for the extracorporeal treatment of blood in an extracorporeal blood circuit (1) by adding citrate for the purpose of anticoagulation, wherein the device (4) comprises an addition device (12) for adding a calcium solution to the extracorporeal blood circuit (1), or for controlling the addition device (12), the procedure includes the following steps: - Outputting a signal to the addition device (12) to change a setting of the addition device (12), wherein the setting corresponds to or causes an addition of calcium, a calcium dosage or concentration or amount or rate; characterized by the steps - Determining the signal taking into account the calcium content or calcium concentration of a substitution solution used in extracorporeal treatment of the blood; and - Determining the range of values ​​of a permissible or approved setting range for the calcium introduced or to be introduced into the extracorporeal blood circulation (1) by means of the addition device (12), in particular its quantity, concentration or dosage, under - Setting a lower limit value for the adjustment range that is considered the smallest permissible value. [2] Control device (20) according to claim 1, wherein the method further comprises the step: - Detect a blood treatment mode set or running on the device (4) for extracorporeal treatment of blood. [3] Control device (20) according to any of the preceding claims, wherein the method further comprises the step: - Determining the lowest permissible threshold value of the setting range according to the formula Ca_Dosis_min=[Ca]_Sub*Q_Sub+[Ca]_Lsg*Q_Ca_minQ_Fil+Q_Ca_min or according to the formula Ca_Dosis_min=[Ca]_Sub*Q_SubQ_Fil where Q_Fil is the sum of at least two flows from the group which includes or consists of at least Q_Sub, Q_Dia, Q_Ci, Q_Hep, and Q_UF, where: Ca-Dose_min minimum calcium dose or the lowest acceptable value within the range; [Ca]_Sub Calcium concentration of the substitute; [Ca]_Lsg Calcium concentration of the calcium solution; Q_Fil filtrate flow; Q_Sub Substitut flow; Q_Dia dialysate flow; Q_Ca_min minimum calcium flow; Q_Ca Calcium flux; Q_Ci citrate flux; Q_Hep Heparin flow; and Q_UF Net flow rate of ultrafiltration. [4] Control device (20) according to any of the preceding claims, wherein the method further comprises the step: - Allowing the user of the device (4) or the addition device (12) to adjust the calcium dosage, quantity or concentration only within the range of the adjustment range and / or not below the lowest permissible value. [5] Control device (20) according to any of the preceding claims, wherein the method further comprises the step: - Issuing a notification when a container (19) for the substitute used has been or is about to be changed, or when the composition or calcium content or concentration of the substitute used has been changed. [6] Control device (20) according to any of the preceding claims, wherein the method further comprises the step: - Adjusting the lower threshold value of the value range considered to be the smallest permissible value due to a change in the delivery rate of the blood pump (7) and / or dialysate pump and / or another pump of the device (4). [7] Control device (20) according to any of the preceding claims, wherein the method further comprises the step: - Allowing the user to lower the calcium dose added by the dosing device below the previously considered minimum acceptable value of the setting range if, after a change in blood flow, the resulting minimum calcium dose is lower than before the change. [8] User interface (31), which is a Control device (20) according to one of claims 1 to 7 or functionally connected with a Control device (20) according to one of claims 1 to 7 is connected to an input device (51) for inputting a calcium dosage, quantity or concentration, the delivery of which is to be effected by means of the control device (20). [9] User interface (31) according to claim 8, comprising a display provided to show the lower value considered to be the least acceptable. [10] Device (4) for extracorporeal treatment of blood, comprising a control device (20) according to any one of claims 1 to 7 and / or a user interface (31) according to any one of claims 8 or 9. [11] Device (4) according to claim 10, configured as a dialysis device, in particular as a hemodiafiltration device or hemofiltration device.

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