CN109641096B

CN109641096B - Blood treatment device and method for operating a blood treatment device

Info

Publication number: CN109641096B
Application number: CN201780052031.3A
Authority: CN
Inventors: 曼弗雷德·魏斯; 阿尔内·彼得斯; 克里斯托夫·维克托; 斯特凡·克雷伯; 格哈德·马格
Original assignee: Fresenius Medical Care Deutschland GmbH
Current assignee: Fresenius Medical Care Deutschland GmbH
Priority date: 2016-08-27
Filing date: 2017-08-14
Publication date: 2022-08-02
Anticipated expiration: 2037-08-14
Also published as: CN109641096A; WO2018041622A1; DE102016010434B4; DE102016010434A1

Abstract

The invention relates to a blood treatment device having an extracorporeal blood circuit I and a fluid system II, which is separated from the extracorporeal blood circuit by a semipermeable membrane 11 of a filter 10, which has a first filter chamber 12 and a second filter chamber 13, wherein the first filter chamber is part of the extracorporeal blood circuit and the second filter chamber is part of the fluid system, and the fluid system comprises means for balancing fresh and used treatment fluid. The invention further relates to a method for operating such a blood treatment device. The blood treatment device according to the invention has a volumetric balancing system with a balancing chamber 1; 20; 50. a balancing chamber 1 according to the invention; 20; 50 is characterized in that the first and second balancing chamber halves 4, 5 of the balancing chamber 1 are separated by a membrane 3, which is a semi-permeable membrane, such that a substance exchange between the first and second chamber halves is possible via the semi-permeable membrane. Thus, the balancing chamber can also be used as a filter.

Description

Blood treatment device and method for operating a blood treatment device

Technical Field

The invention relates to a blood treatment device having an extracorporeal blood circuit and a fluid system which is separated from the extracorporeal blood circuit by a semi-permeable membrane of a filter, said filter having a first filter chamber and a second filter chamber, wherein the first filter chamber is part of the extracorporeal blood circuit and the second filter chamber is part of the fluid system, and the fluid system comprises means for balancing fresh treatment fluid and used treatment fluid. The invention further relates to a method for operating such a blood treatment device.

Background

In order to remove urinary excretion and to perform fluid removal, different methods are used in chronic renal failure for instrumental blood purification or blood treatment. In Hemodialysis (HD), diffusive substance transport is dominant, whereas in Hemofiltration (HF), convective substance transport takes place via the semi-permeable membrane of the filter. The combination of these two methods is Hemodiafiltration (HDF).

Due to the large exchange capacity, the following necessities exist in the above-described method: the fresh dialysis fluid delivered to the filter and the used dialysis fluid derived from the filter are accurately balanced taking into account the amount of fluid extracted from the patient via the membrane of the filter over the entire treatment time. The amount of liquid extracted from the patient by ultrafiltration can be partially or completely re-delivered to the patient as replacement liquid when the dehydration is controlled. The delivery of the circuit substitution fluid upstream of the dialyzer in an extracorporeal blood circuit is referred to as pre-dilution, while the delivery of the substitution fluid downstream of the dialyzer is referred to as post-dilution. These two methods can also be combined with each other.

Very high demands are made on the accuracy of the balancing. The premise is that: fresh and used dialysate can be accurately balanced by means of a balancing system.

The prior art includes balancing systems having a balancing chamber divided into two balancing chamber halves by a flexible membrane.

DE-a-2838414 describes a dialysis device with a balancing system having two balancing chambers, the balancing chamber halves of which are alternately filled with fresh dialysis fluid, with used dialysis fluid being discarded from the respective other chamber half. Thus, the part of the liquid circuit comprised between the balancing system and the dialyzer behaves like a closed system, the volume of which is constant. Liquid can be extracted from the closed system via an ultrafiltration pump. The membranes of the known balancing chambers are impermeable to the substances contained in the dialysis fluid, so that no substance exchange can take place.

Balancing systems are also known which have only one balancing chamber which is not divided into two chamber halves by a membrane. In such a balancing chamber, the used dialysate present in the chamber is squeezed out by the inflowing dialysate.

In addition to accurately balancing fresh and used dialysate, it is also important to establish a safety barrier between the extracorporeal blood circuit and the machine part of the blood treatment apparatus. Furthermore, a compact structure of the blood treatment apparatus is sought.

Disclosure of Invention

The invention is based on the object of providing a blood treatment device with improved balancing and to provide a method for operating a blood treatment device which allows improved balancing.

The blood treatment device according to the invention has a volumetric balancing system with a balancing chamber. The balancing chamber according to the invention is characterized in that the first balancing chamber half and the second balancing chamber half of the balancing chamber are separated by a membrane, which is a semi-permeable membrane, such that a substance exchange between the first and second chamber halves via the semi-permeable membrane is possible. Thus, the balancing chamber can also be used as a filter.

The balancing chamber according to the invention can be integrated in different ways into the liquid system of the blood treatment apparatus. The balancing chamber can be used in different blood treatment methods, for example in hemodialysis or hemofiltration or a blood treatment method with hemodialysis and hemofiltration (hemodiafiltration).

The treatment liquid can be conveyed in a known manner by means of a pump in the liquid line, and the liquid line can be blocked by means of a blocking mechanism. The fluid line can be configured such that the treatment fluid, in particular the dialysis fluid, flows along the semipermeable membrane through one chamber half, along the membrane through the other chamber half, or flows via the membrane from one chamber half into the other chamber half. The liquid flow in the respective other chamber half can be interrupted in this case.

In the flow of liquid from one chamber half into the other, substances with low permeability, such as urea or beta 2 microglobulin, are blocked, while substances with higher permeability, such as water, are able to pass through the semi-permeable membrane. Thus, during equilibration, a particular substance may be trapped or concentrated in one of the two chamber halves.

The liquid system can comprise a liquid line connected to the inlet and/or outlet of the first balancing chamber half and/or a liquid line connected to the inlet and/or outlet of the second balancing chamber half. The control of the pump and the blocking mechanism can be performed by the control unit. The operation of the blood treatment apparatus can be carried out in successive working cycles, which can each comprise two working cycles. The duty cycle can also include other duty cycles.

In a first embodiment, the control unit for actuating the pump and the blocking mechanism is configured such that, in a first operating cycle of one of the successive operating cycles, the treatment fluid, in particular the dialysis fluid, flows from the first balancing chamber half into the second balancing chamber half via the semipermeable membrane of the balancing chamber, and that, in a second operating cycle of the successive operating cycle, the treatment fluid flows through the first balancing chamber half.

During a first operating cycle of the first embodiment, the treatment liquid, in particular the dialysis liquid, can flow from the second filter chamber of the filter, which is part of the liquid system, into the first balance chamber half and from the second balance chamber half into the second filter chamber, so that the treatment liquid is circulated in the liquid system (hemodialysis). Here, the treatment fluid flows through the semi-permeable membrane of the balancing chamber. Alternatively, the fluid can be extracted from the extracorporeal blood circuit via the semipermeable membrane of the filter in the first operating cycle. This liquid can flow from the second filter chamber into the first balance chamber half and from the second balance chamber half to the junction of the blood conveying line leading to the first filter chamber (pre-dilution) and/or the discharge line leaving the first filter chamber (post-dilution) (hemofiltration).

During the second cycle of the first embodiment, an exchange of fresh treatment fluid and used treatment fluid can take place. Fresh dialysate can be provided in the dialysate source and directed into the drain. Fresh dialysate flowing to the first balance chamber half squeezes out dialysate in the first and second balance chamber halves, which can flow out into the drain. The volume of the dialysis fluid which is important for the balancing is determined by the volume of the balancing chamber halves.

The metering cycle (Taktung) can also be based on substance concentration, flow rate, pressure, etc., wherein these variables can be measured by suitable sensors in the liquid system.

An alternative embodiment provides that the control unit for actuating the pump and the blocking mechanism is configured such that, in a first working cycle of one of the successive working cycles, the treatment fluid flows from the first balancing chamber half into the second balancing chamber half via the semipermeable membrane of the balancing chamber, and, in a second working cycle of the successive working cycle, the treatment fluid flows from the second balancing chamber half into the first balancing chamber half via the semipermeable membrane of the balancing chamber.

In a first operating cycle of the alternative embodiment of the locking tongue, the treatment liquid can flow again from the second filter chamber of the filter as part of the liquid system into the first balance chamber half and from the second balance chamber half into the second filter chamber, so that the dialysis liquid is circulated in the liquid system (hemodialysis). Here again, the treatment fluid flows through the semipermeable membrane of the balancing chamber. Alternatively, the fluid can be extracted from the extracorporeal blood circuit via the semipermeable membrane of the filter in the first operating cycle. Fluid can flow from the second filter chamber into the first balance chamber half and from the second balance chamber half to a junction of a blood delivery line leading to the first filter chamber (pre-dilution) and/or a drain line exiting the first filter chamber (post-dilution) (hemofiltration).

In a second working cycle of the alternative embodiment, a fresh treatment fluid and a used treatment fluid can be exchanged. Fresh dialysate flowing to the second balance chamber half squeezes out dialysate in the first and second balance chambers, which can flow out into the drain.

Hemodialysis and hemofiltration can also be combined with each other.

The blood treatment device according to the invention can also have an ultrafiltration device, by means of which fluid can be extracted from the fluid system or from the extracorporeal blood circuit via the semipermeable membrane of the filter. Such ultrafiltration devices are known in the art.

The blood treatment apparatus according to the invention and the method according to the invention allow balancing and separation of substances to be achieved by using a filter as a balancing chamber. An additional barrier can be achieved by means of the balancing chamber according to the invention. Furthermore, it is feasible to concentrate or dilute a specific substance in one of the balancing chamber halves. By means of the balancing chamber according to the invention, the entire blood treatment apparatus can have a compact structure.

Drawings

Various embodiments of the present invention are described in detail below with reference to the accompanying drawings.

The figures show:

figure 1A shows a simplified schematic view of the balancing chamber of the blood treatment apparatus according to the invention,

figure 1B shows a simplified schematic view of an equalizing chamber constructed as a hollow fiber filter 1,

figure 2A shows a first on state of the balance chamber during one operating cycle of the operating cycle,

figure 2B shows a second on state of the balance chamber during one duty cycle of the duty cycle,

figure 2C shows a third on-state of the balance chamber during one working cycle of the working cycle,

figure 2D shows a fourth on-state of the balance chamber during one working cycle of the working cycle,

figure 2E shows the fifth on state of the balance chamber during one operating cycle of the operating cycle,

figure 2F shows a sixth on state of the balance chamber during one working cycle of the working cycle,

figure 3 shows a first embodiment of a blood treatment apparatus according to the invention,

figure 4 shows a second embodiment of the blood treatment apparatus according to the invention,

fig. 5 shows a third embodiment of a blood treatment apparatus according to the invention, an

Fig. 6 shows a fourth embodiment of the blood treatment apparatus according to the invention.

Detailed Description

Fig. 1A shows a simplified schematic view of an equalizing chamber 1. The balancing chamber 1 has a rigid housing 2 which is divided by a semi-permeable membrane 3 (which is a rigid membrane) into a first balancing chamber half 4 and a second balancing chamber half 5. The semi-permeable membrane 3 is impermeable to substances with low permeability, such as urea or beta 2 microglobulin, and permeable to substances with high permeability, such as water. In the case of a symmetrical division of the balancing chamber 1, the two chamber halves have the same volume. Alternatively, the chamber halves may be asymmetrically divided with different volumes.

The first balance chamber half 4 has an inlet 4A and an outlet 4B, while the second balance chamber half 5 has an inlet 5A and an outlet 5B. Liquid lines, such as hose lines, can be connected to the inlet and outlet. The supply or discharge of liquid into or out of the chamber halves can be interrupted by means of a shut-off mechanism 6, which is only shown implicitly. The arrows illustrate the direction of flow into or out of the chamber halves.

Fig. 1B shows an exemplary embodiment of an equalization chamber 1, which is designed as a hollow fiber filter. Substances with low permeability are shown as light dots, while substances with high permeability are shown as dark dots. The outlet 4B of the first chamber half and the inlet 5A of the second chamber half are closed, while the inlet 4A of the first balance chamber half and the outlet 5B of the second balance chamber half are open. For example, if the substance with high permeability is water and the substance with low permeability is urea, the water with high permeability flows from the first half of the balancing chamber into the second half of the balancing chamber through the semipermeable membrane formed by the hollow fiber bundle. This indicates that the semi-permeable membrane blocks substances with low permeability, such as urea.

Different on-states of the balancing chamber of fig. 1A are described in the following with reference to fig. 2A to 2F. The individual on-states are indicated in the figure by periods a to F. These periods can be individual duty cycles of one duty cycle, wherein a plurality of duty cycles can follow one another. In one working cycle, the working cycles can follow one another in different orders. Transitional states, for example states in which only one inlet or outlet is open or all inlets or outlets are closed, can be set between the periods.

Fig. 2A shows an on state in which the inlet 4A of the first balance chamber half 4 and the outlet 5B of the second balance chamber half 5 are open, while the outlet 4B of the first balance chamber half 4 and the inlet 5A of the second balance chamber half 5 are closed. A substance with high permeability flows through the balancing chamber 1, wherein the substance with low permeability is blocked by the semi-permeable membrane (period a). The volume of liquid flowing into the first balancing chamber half 4 squeezes out the same volume of liquid that is in the balancing chamber 1.

Fig. 2B shows an on state in which the inlet 4A and the outlet 4B of the first balance chamber half 4 are open and the inlet 5A and the outlet 5B of the second balance chamber half 5 are closed. The liquid flows through the first balance chamber half 4, wherein substances with a high permeability can enter the second balance chamber half 5 (period B).

Fig. 2C shows an on state in which the inlet 4A of the first balance chamber half 4 and the outlet 5B of the second balance chamber half 5 are closed, while the outlet 4B of the first balance chamber half 4 and the inlet 5A of the second balance chamber half 5 are open. A substance with high permeability flows through the balancing chamber 1, wherein the substance with low permeability is blocked by the semi-permeable membrane 3 (cycle C).

Fig. 2D shows an on state in which the inlet 4A and the outlet 4B of the first balance chamber half 4 are closed and the inlet 5A and the outlet 5B of the second balance chamber half 5 are open. The liquid flows through the second balance chamber half 5, wherein substances with a high permeability can enter the first balance chamber half 4 (period B).

Fig. 2E and 2F show the on state of fig. 2A or 2B, in which a liquid of a substance having low permeability and a substance having high permeability is supplied to the inlet (fig. 2E), or a liquid of a substance having high permeability is supplied to the inlet (fig. 2F). This indicates that: the low-permeability substances are blocked by the semi-permeable membrane 3 and do not enter the second balancing chamber half 5.

Fig. 3 shows a simplified schematic representation of a blood treatment apparatus according to the invention with a balancing chamber according to the invention. In the present embodiment, the blood treatment apparatus is a hemodialysis apparatus.

The hemodialysis apparatus has a filter 10 (dialyzer) divided by a semi-permeable membrane 11 into a first filtration compartment 12 and a second filtration compartment 13. The blood feeding line 14 is connected to the inlet 12A of the first filtering chamber 12, and the blood discharging line 15 is connected to the outlet 12B of the first filtering chamber 12. The patient's blood is conveyed in an extracorporeal blood circuit I by means of a blood pump 16 arranged in a blood conveying line 14.

The fluid system II has an equilibrium chamber 17 described with reference to fig. 1A and 1B and fig. 2A to 2F, which is divided by a semi-permeable membrane 18 into a first equilibrium chamber half 19 and a second equilibrium chamber half 20. The first balance chamber half 19 has an inlet 19A and an outlet 19B, while the second balance chamber half 20 has only one outlet 20B.

Furthermore, the fluid system II has a dialysate source 21 for fresh dialysate, which is connected to the inlet 19A of the first balance chamber half 19 via a first fluid line 22.

The dialysis liquid is conveyed into the first balance chamber half 19 by means of a first pump 23 arranged in the first liquid line 22. Upstream of the first pump, a first shut-off device 24, for example an electromagnetically actuable hose clamp, is arranged in the first liquid line 22.

The outlet 13B of the second filtering chamber 13 is connected to the first liquid line 22 via a second liquid line 25. A connection point 26 at which the second liquid line 25 is connected to the first liquid line 22 is located between the first shut-off mechanism and the first pump 23. However, the second liquid line 25 can also be connected downstream of the pump to the first liquid line or to the inlet of the first balancing chamber half. A second shut-off mechanism 27 is provided in the second liquid line 25.

The outlet 19B of the first balance chamber half 19 is connected via a third fluid line 28 to a drain 29 so that used dialysis fluid can flow out. A third shut-off means 30 is provided in the third liquid line 28.

The outlet 20B of the second equilibrium chamber half 20 is connected to the inlet 13A of the second filter chamber 13 via a fourth liquid line 31, in which fourth liquid line 31 a fourth shut-off means 32 is arranged. In the fourth fluid line 31, a second pump 33 is provided, which conveys the dialysis fluid from the second balancing chamber half 20 into the second filter chamber 13.

The blood treatment apparatus can also have an ultrafiltration device with an ultrafiltration pump 34, which removes the ultrafiltrate from the fluid system II. An ultrafiltration pump 34 is arranged in the fifth liquid line 35, the fifth liquid line 35 being connected to the second liquid line 25.

Furthermore, the blood treatment apparatus has a central control unit 36 which is connected via control lines, not shown, to the first and second pumps 23, 33 and the ultrafiltration pump 34 in the liquid system II and to the blood pump 16 in the extracorporeal blood circuit I and to the shut-off means 24, 27, 30, 32 in the liquid system I, so that the flow rate of the pumps can be set and the shut-off means can be operated. The control unit 36 can have a general processor, a Digital Signal Processor (DSP) for continuously processing digital signals, a microprocessor, an Application Specific Integrated Circuit (ASIC), an integrated circuit (FPGA) or other Integrated Circuits (ICs) or hardware components consisting of logic elements to perform the individual method steps. A data processing program (software) can be run on the hardware components to perform the method steps. A plurality of different components or combinations thereof are also possible.

The control unit 36 is configured such that the subsequent work cycles are performed in work cycles that are successive to each other.

The successive operating cycles each comprise two operating cycles. In a first operating cycle, the control unit 36 actuates the blocking means such that the first and third blocking means 24, 30 are closed and the second and fourth blocking means 27, 32 are open. Thus, the balance chamber operates in the on state of the cycle C (fig. 2C). In a second operating cycle, the control unit actuates the blocking means in such a way that the first and third blocking means 24, 30 are open and the second and fourth blocking means 27, 32 are closed. Thus, the balance chamber operates in the on state of period D (fig. 2D). Followed by a second duty cycle, etc.

In a first working cycle, the dialysate flows from the second filtration compartment 13 into the first balance chamber half 19, from the first balance chamber half through the semi-permeable membrane 18 into the second balance chamber half 20, from the second balance chamber half into the second filtration compartment 13 (dialysate compartment) and from the second filtration compartment 13 into the first balance chamber half 19 again. Substances with low permeability in the dialysis fluid, such as urea, are blocked by the semi-permeable membrane 18, so that these substances are concentrated in the first balancing chamber half. The dialysate is transported by the first and second pumps 23, 33.

In the second operating cycle, the dialysate flows from the dialysate source 21 into the first balance chamber half 19 and from the first balance chamber half into the drain 29, so that used dialysate can flow out. The dialysate is delivered by a first pump.

Cycle C is used to exchange fluid in the dialyzer, where blood and dialysate flow concurrently (Gleichstrom). However, in a corresponding configuration, the flow of blood and dialysate can also be performed counter-currently. The period D is used for exchanging liquid in the balancing chamber with a filtering function. In this application, the advantage of using a balancing chamber with a filtering function is that it provides an additional barrier in the fluid system with respect to the patient.

Fig. 4 shows an embodiment in which the blood treatment apparatus is a blood filtration apparatus. The blood filtration apparatus has a filter 10 divided into a first filtration chamber 12 and a second filtration chamber 13 by a semi-permeable membrane 11. A blood delivery line 14 is connected to the inlet 12A of the first filtering chamber 12 and a blood evacuation line 15 is connected to the outlet 12B of the first filtering chamber 12. The patient's blood is conveyed in an extracorporeal blood circuit I by means of a blood pump 16 arranged in the blood conveying line 14.

The liquid system II has the equilibrium chamber 17 described with reference to fig. 1A and 1B and fig. 2A to 2F. The first balance chamber half 19 has an inlet 19A and an outlet 19B, while the second balance chamber half 20 has only one outlet 20B.

Furthermore, the fluid system II has a dialysate source 21 for fresh dialysate, which is connected via a first fluid line 37 to a branch 38, which branch 38 leads to the inlet 19A of the first balance chamber half 19. The dialysate can be conveyed from the dialysate source 21 into the first balance chamber half 19 by means of a first pump 39, which is arranged in the first liquid line 37. Upstream of the first pump 39, a first shut-off mechanism 40, for example an electromagnetically actuable hose clamp, is arranged in the first liquid line 37.

The outlet 13B of the second filtering chamber 13 is connected via a second liquid conduit 41 to a branch 38 leading to the inlet 19A of the first balancing chamber half 19. A second pump 42 is provided in the second liquid line 41. A second shut-off mechanism 43 is provided in the second liquid line 41 upstream of the second pump 42.

The outlet 19B of the first balance chamber half 19 is connected to the drain 29 via a third liquid line 44. A third shut-off means 45 is provided in the third liquid line 44.

A fourth liquid line 46, in which a fourth shut-off means 47 is arranged, exits from the outlet 20B of the second equilibrium chamber half 20. The fourth liquid line 46 branches into a first and a

second section

46A, 46B, wherein the first section 46A leads to the connection of the blood supply line 14 upstream of the filter 12, and the second section 46B leads to the connection of the blood discharge line 15 downstream of the filter, so that the substitution fluid can be supplied to the extracorporeal blood circuit upstream of the filter (pre-dilution) or downstream of the filter (post-dilution). In the first and second section of the fourth liquid line 46, a further shut-off

mechanism

48A, 48B is provided, respectively, so that switching between pre-dilution and/or post-dilution is possible.

The blood treatment apparatus can also have an ultrafiltration device with an ultrafiltration pump 34 which removes the ultrafiltrate from the fluid system I. The ultrafiltration pump 34 is arranged in a fifth liquid line 35, which is connected to the second liquid line 41.

In the blood filtration apparatus, the control unit 36 is configured such that the subsequent work cycles are performed in work cycles that are successive to each other.

The successive operating cycles each comprise two operating cycles. During the first operating cycle, the control unit 36 actuates the blocking mechanism such that the second and

fourth blocking mechanisms

43, 47 are open and the first and

third blocking mechanisms

40, 45 are closed. Thus, in the horizontally mirrored view (fig. 2E), the balance chamber operates in the on state of cycle E. In a second operating cycle, the control unit actuates the blocking mechanism such that the second and

fourth blocking mechanism

43, 47 are closed and the first and

third blocking mechanism

40, 45 are open. Thus, in the horizontally mirrored view (fig. 2F), the balance chamber operates in the on state of cycle F. Followed by a second duty cycle, etc.

During a first operating cycle, liquid flows from the second filter chamber 13 into the first balance chamber half 19, from the first balance chamber half through the semi-permeable membrane 18 into the second balance chamber half 20 and from the second balance chamber half into the blood supply line 14 and/or the blood discharge line 15. Liquid is removed from the second filter chamber 13 by means of the second pump 42. Substances with low permeability are blocked by the semi-permeable membrane 18, so that these substances cannot enter the extracorporeal blood circuit I and concentrate in the first balance chamber half 19.

In the second operating cycle, the dialysate flows from the dialysate source 21 into the first balance chamber half 19 and from the first balance chamber half into the drain 29, so that used dialysate can flow out.

In cycle E, blood filtration is performed, and in cycle F, liquid exchange is performed in the equilibrium chamber having a filtration function. The advantage of using a balancing chamber with a filtering function in this application is that it provides a barrier to exchange fluid with respect to the patient.

Fig. 5 shows a further embodiment, in which the blood treatment apparatus is a hemodialysis apparatus. The hemodialysis apparatus has a filter 10 (dialyzer) divided by a semi-permeable membrane 11 into a first filtering chamber 12 and a second filtering chamber 13. The blood feeding line 14 is connected to the inlet 12A of the first filtering chamber 12, and the blood discharging line 15 is connected to the outlet 12B of the first filtering chamber 12. The patient's blood is conveyed in an extracorporeal blood circuit I by means of a blood pump 16 arranged in a blood conveying line 14.

The fluid system II has an equilibrium chamber 50 described with reference to fig. 1A and 1B and fig. 2A to 2F, which is divided by a semi-permeable membrane 51 into a first equilibrium chamber half 52 and a second equilibrium chamber half 53. The first balance chamber half 52 has an inlet 52A and an outlet 52B, while the second balance chamber half 53 has an inlet 53A and an outlet 53B.

The outlet 13B of the second filtering chamber 13 is connected to the inlet 52A of the first balancing chamber half 52 via a first liquid line 54. A first pump 55 is provided in the first liquid line 54. Downstream of the first pump 55, a first shut-off mechanism 56 is provided in the first liquid line 54.

A second liquid line 57, in which a second shut-off means 58 is arranged, leads from the outlet 52B of the first balance chamber half 52 to the discharge opening 29.

Furthermore, the fluid system I has a fresh dialysate source 21 which is connected via a third fluid line 59 to the inlet 53A of the second balance chamber half 53. The dialysis liquid can be conveyed into the second balancing chamber half by means of a second pump 60, which is arranged in the third liquid line 59. Downstream of the second pump 60, a third shut-off mechanism 61, for example an electromagnetically actuable hose clamp, is provided in the third liquid line 59.

The outlet 53B of the second equilibrium chamber half 53 is connected to the inlet 13A of the second filtration chamber 13 via a fourth liquid line 62, in which fourth liquid line 62 a fourth shut-off means 63 is provided.

The blood treatment apparatus can also have an ultrafiltration device with an ultrafiltration pump 34, which removes the ultrafiltrate from the fluid system I. The ultrafiltration pump 34 is arranged in a fifth liquid line 35 which is connected to the first liquid line 54 upstream of the first pump 55.

In this embodiment of the hemodialysis apparatus, the control unit 36 is configured such that the subsequent duty cycles are performed in duty cycles that are consecutive to each other.

The successive operating cycles each comprise two operating cycles. During the first operating cycle, the control unit 36 actuates the blocking means such that the first and fourth blocking means 56, 63 are open and the second and third blocking means 58, 61 are closed. Therefore, the balance chamber 50 operates in the on state of the period a (fig. 2A). In a second operating cycle, the control unit actuates the blocking means such that the first and fourth blocking means 56, 63 are closed and the second and third blocking means 58, 61 are open. Thus, the balance chamber operates in the on state of cycle C (fig. 2C). Followed by a second duty cycle, etc.

In the first working cycle, the dialysate flows from the second filtration chamber 13 (dialysate chamber) into the first balance chamber half 52, from the first balance chamber half through the semipermeable membrane 51 into the second balance chamber half 53, from the second balance chamber half into the second filtration chamber 13 (dialysate chamber) and from the second filtration chamber 13 into the first balance chamber half again. The dialysis fluid is transported by means of a first pump 55. Substances with low permeability are blocked by the semi-permeable membrane so that these substances are concentrated in the first balancing chamber half.

In the second operating cycle, the dialysate flows from the dialysate source 21 into the second balance chamber half 53 and from there into the drain 29, so that used dialysate can flow out. The dialysate is transported by means of a second pump 60.

Cycle a is used to circulate dialysate through the second filtration chamber (dialysate chamber) where blood and dialysate flow counter-currently. Alternatively, however, the flow of blood and dialysate can take place downstream with a corresponding configuration. Cycle C is used for liquid exchange in the balancing chamber with filtering function. In this application, the use of a balancing chamber with a filtering function has the advantage that mixing of fresh dialysis fluid with used dialysis fluid is avoided.

Fig. 6 shows another embodiment, in which the blood treatment apparatus is a blood filtration apparatus. The blood filtration apparatus has a filter 10 which is divided into a first filtration chamber 12 and a second filtration chamber 13 by a semi-permeable membrane 11. A blood delivery line 14 is connected to the inlet 12A of the first filtering chamber 12 and a blood evacuation line 15 is connected to the outlet 12B of the first filtering chamber 12. The patient's blood is conveyed in an extracorporeal blood circuit I by means of a blood pump 16 arranged in the blood conveying line 14.

The fluid system I has an equilibrium chamber 50 described with reference to fig. 1A and 1B and fig. 2A to 2F, which is divided by a semi-permeable membrane 51 into a first equilibrium chamber half 52 and a second equilibrium chamber half 53. The first balance chamber half 52 has an inlet 52A and an outlet 52B, while the second balance chamber half 53 has an inlet 53A and an outlet 53B.

In the blood filtration apparatus, the second filter chamber 13 does not have an inlet, but only one outlet 13B. The outlet 13B of the second filter chamber 13 is connected to the inlet 52A of the first balance chamber half 52 via a first liquid line 54. A first pump 55 is disposed in the first liquid line 54.

Downstream of the first pump 55, a first shut-off mechanism 56 is provided in the first liquid line 54.

Furthermore, the fluid system I has a fresh dialysate source 21 which is connected via a third fluid line 59 to the inlet 53A of the second balance chamber half 53. The dialysis fluid can be conveyed into the second balancing chamber half 53 by means of a second pump 60, which is arranged in a third fluid line 59. Downstream of the second pump 60, a third shut-off mechanism 61, for example an electromagnetically actuable hose clamp, is provided in the third liquid line 59.

A fourth liquid line 70, in which a fourth shut-off means 71 is arranged, exits from the outlet 53A of the second balance chamber half. Downstream of the fourth shut-off means 71, the fourth liquid line 70 branches into a first and a

second section

70A, 70B, wherein the first section 70A leads to the connection of the blood supply line 14 upstream of the filter 10 and the second section 70B leads to the connection of the blood discharge line 15 downstream of the filter 10, so that the substitution fluid can be supplied to the extracorporeal blood circuit upstream of the filter (predilution) or downstream of the filter (postdilution). In the first and second sections of the fourth liquid line 70, a further shut-off mechanism 71A, 71B is provided, respectively, so that switching between pre-dilution and/or post-dilution is possible. The displacement liquid is delivered by means of a third pump 73 (displacement liquid pump) which is arranged in the fourth liquid line 70 downstream of the third shut-off mechanism 71.

The successive operating cycles each comprise two operating cycles. During the first operating cycle, the control unit 36 actuates the blocking means such that the first and fourth blocking means 56, 71 are open and the second and third blocking means 58, 61 are closed. Thus, the balance chamber operates in the on state of the period a (fig. 2A). In a second operating cycle, the control unit 36 actuates the blocking means such that the first and fourth blocking means 56, 71 are closed and the second and third blocking means 58, 61 are open. Thus, the balance chamber operates in the on state of cycle C (fig. 2C). Followed by a second duty cycle, etc.

In the first working cycle, liquid is removed from the second filter chamber 12 by means of the first pump 55. The fluid flows into the first balance chamber half 52, from there through the semipermeable membrane 51 into the second balance chamber half 53 and from there to the blood supply or

discharge line

14, 15. Substances with low permeability are blocked by the semi-permeable membrane 51, so that these substances cannot enter the extracorporeal blood circuit I and can be concentrated in the first balance chamber half 52.

In the second operating cycle, the dialysate flows from the dialysate source 21 into the second balancing chamber half 53 and from the first balancing chamber half 52 into the drain 29, so that used dialysate can flow out. The dialysate is transported by means of a second pump 60.

In cycle a, blood filtration is performed, and in cycle C, liquid exchange is performed in the equilibrium chamber having a filtration function. In this application, the use of a balancing chamber with a filtering function has the advantage that mixing of the replacement liquid and the filtered-off liquid is avoided.

Claims

1. A blood treatment apparatus having an extracorporeal blood circuit (I) and a fluid system (II) which is separated from the extracorporeal blood circuit by a semipermeable membrane (11) of a filter (10) having a first filter chamber (12) and a second filter chamber (13), wherein the first filter chamber is part of the extracorporeal blood circuit and the second filter chamber is part of the fluid system, and the fluid system comprises a volumetric balancing system for balancing fresh and used treatment fluid, the volumetric balancing system having a balancing chamber which constitutes a fluid line for balancing fresh dialysis fluid which is fed to the filter (10) and used dialysis fluid which leaves from the filter, and the fluid system (II) having a fluid line which leads to and leaves from the balancing chamber, and the liquid system has a pump (23, 33; 39) for delivering the treatment liquid, a blocking mechanism (24, 27, 30, 32; 40, 43, 45, 47) for blocking the liquid line,

characterized in that the device for balancing fresh and used treatment fluids is designed as a balancing chamber with a semi-permeable membrane which divides the balancing chamber into a first balancing chamber half and a second balancing chamber half.

2. A blood treatment apparatus according to claim 1, wherein the liquid system (II) comprises a first liquid line leading to the inlet of the first balance chamber half and a third liquid line exiting from the outlet of the first balance chamber half and a fourth liquid line exiting from the outlet of the second balance chamber half,

a control unit (36) for actuating the pump and the blocking mechanism is provided, which is configured such that, in a first operating cycle of one of the operating cycles that follow one another, the treatment liquid flows from the first balancing chamber half into the second balancing chamber half via the semipermeable membrane of the balancing chamber,

and in a second duty cycle of the successive duty cycles, the therapeutic liquid flows through the first balance chamber half.

3. The blood treatment apparatus according to claim 2,

it is characterized in that the preparation method is characterized in that,

the blood treatment device has a fresh dialysis fluid source (21) and a used dialysis fluid drain (29),

a first fluid line leading to the inlet of the first balance chamber half is connected to the dialysate source (21) and a third fluid line leading from the outlet of the first balance chamber half is connected to the drain (29),

a fourth liquid conduit exiting from the outlet of the second balancing chamber half leads to the inlet of the second filtering chamber (13), and

a second liquid conduit exits from an outlet of the second filter chamber (13), the second liquid conduit leading to an inlet of the first balance chamber half or to the first liquid conduit leading to an inlet of the first balance chamber half,

wherein for operating the blood treatment apparatus as a hemodialysis apparatus, a control unit (36) for operating the pump and blocking mechanism is configured such that in a first duty cycle of one of the successive duty cycles, the treatment liquid flows from the second balancing chamber half into the second filtering chamber (13) and from the second filtering chamber into the first balancing chamber half, such that the treatment liquid flows from the first balancing chamber half into the second balancing chamber half via the semi-permeable membrane of the balancing chamber,

and in a second working cycle of a successive working cycle, the treatment liquid flows from the dialysate source (21) through the first balance chamber half to the drain (29).

4. A blood treatment apparatus according to claim 2, characterized in that the blood treatment apparatus has a dialysate source (21) for fresh dialysate and a drain (29) for used dialysate,

a first liquid line leading to the inlet of the first balance chamber half is connected to the dialysate source (21) and a third liquid line exiting from the outlet of the first balance chamber half is connected to the drain (29),

a fourth liquid line exiting from the outlet of the second balancing chamber half leads to a blood delivery line (14) of the extracorporeal blood circuit (I) leading to the first filtering chamber (12) and/or to a blood evacuation line (15) exiting from the first filtering chamber

A further second liquid line exits from the outlet of the second filter chamber (13), said further second liquid line leading to the inlet of the first balancing chamber half and the above-mentioned first liquid line leading to the inlet of the first balancing chamber half,

wherein for operating the blood treatment apparatus as a blood filtration apparatus, the control unit (36) for operating the pump and blocking mechanism is configured such that in a first working cycle of one of the successive working cycles, treatment liquid flows from the second balancing chamber half into the blood conveying line (14) leading to the first filtration chamber and/or the blood discharge line (15) exiting from the first filtration chamber such that treatment liquid flows from the first filtration chamber half into the second balancing chamber half via the semi-permeable membrane of the balancing chamber,

and in a second working cycle of the successive working cycle, the treatment liquid flows from the dialysate source (21) through the first balance chamber half to the drain (29).

5. The blood treatment apparatus according to claim 1,

it is characterized in that the preparation method is characterized in that,

the liquid system (II) comprises: a first liquid line leading to an inlet of the first balance chamber half; and a second liquid line exiting from an outlet of the first balance chamber half; and a third liquid line leading to an inlet of the second balance chamber half; and a fourth liquid line exiting from an outlet of the second balance chamber half,

a control unit (36) for operating the pump and the blocking mechanism is provided, the control unit being configured such that, in a first working cycle of one of the successive working cycles, therapeutic liquid flows from the first balancing chamber half into the second balancing chamber half via the semi-permeable membrane of the balancing chamber,

and during a second working cycle of a successive working cycle, therapeutic fluid flows from the second balance chamber half into the first balance chamber half via the semi-permeable membrane of the balance chamber.

6. The blood treatment apparatus according to claim 5,

it is characterized in that the preparation method is characterized in that,

a third liquid line leading to the inlet of the second balance chamber half is connected to the dialysate source (21) and a second liquid line exiting from the outlet of the first balance chamber half is connected to the drain (29),

a fourth liquid conduit leading from the outlet of the second balancing chamber half to the inlet of the second filtering chamber (13), and

a first liquid conduit exits from an outlet of the second filter chamber (13), the first liquid conduit leading to an inlet of the first balancing chamber half,

wherein for operating the blood treatment apparatus as a hemodialysis apparatus, a control unit (36) for operating the pump and the blocking mechanism is configured such that in a first working cycle of one of the successive working cycles, treatment liquid flows from the second balancing chamber half into the second filtering chamber (13) and from the second filtering chamber into the first balancing chamber half, such that the treatment liquid flows from the first balancing chamber half into the second balancing chamber half via the semi-permeable membrane of the balancing chamber,

and in a second working cycle of a successive working cycle, therapeutic liquid flows from the dialysate source (21) into the second balance chamber half and from the first balance chamber half to the discharge (29), such that therapeutic liquid flows from the second balance chamber half into the first balance chamber half via the semi-permeable membrane of the balance chamber.

7. The blood treatment apparatus according to claim 5,

it is characterized in that the preparation method is characterized in that,

a fourth liquid line exiting from the outlet of the second balancing chamber half is directed to a blood delivery line (14) of the extracorporeal blood circuit (I) leading to the first filtering chamber and/or to a blood evacuation line (15) exiting from the first filtering chamber,

a first liquid conduit leading to the inlet of the first filter chamber half exits from the outlet of the second filter chamber (13),

wherein for operating the blood treatment apparatus as a blood filtration apparatus, the control unit (36) for operating the pump and the blocking mechanism is configured such that, in a first working cycle of one of the successive working cycles, the treatment liquid flows from the first balancing chamber half into the blood conveying line (14) leading to the first filtration chamber and/or the blood discharge line (15) exiting from the first filtration chamber, such that the treatment liquid flows from the first balancing chamber half into the second balancing chamber half via the semi-permeable membrane of the balancing chamber,

and in a second working cycle of a successive working cycle, treatment liquid flows from the dialysate source (21) into the second balance chamber half and from the second balance chamber half to the discharge (29), such that treatment liquid flows from the second balance chamber half into the first balance chamber half via the semi-permeable membrane of the balance chamber.

8. Blood treatment apparatus according to any one of claims 1 to 7,

it is characterized in that the preparation method is characterized in that,

an ultrafiltration device is provided for extracting liquid from the liquid system.