HK40023696B - Treatment apparatus for withdrawing blood from an extracorporeal blood circuit - Google Patents

Description

The present invention relates to a blood treatment device as defined in the general concept of claim 1.

In the case of extracorporeal blood treatment, great attention should be paid to the detection and elimination of any gas or air traps in an extracorporeal blood circulation used for blood treatment.

In addition, the use of extracorporeal circulation is usually a disposable item and is disposed of after use. It may be beneficial to remove fluids from the extracorporeal circulation following a blood treatment session for a variety of reasons, including hygiene issues and the cost of disposing of used extracorporeal circulation.

Document DE10245619 describes a device for returning blood from a blood treatment device, preferably a dialysis device. The replacement pump contained in the treatment device displaces the blood by means of appropriately promoted replacement fluid until it is detected in appropriate detectors that blood instead of replacement fluid is flowing back into the line. From this point on, the blood volume is controlled until it reaches the line outlet of the appropriate line. One of the tasks of the present invention is to specify another treatment device for removing blood from an extracorporeal bloodstream after completing an extracorporeal bloodstream treatment. The purpose is to specify a remote device for detecting and/or analyzing which pores of air are present within an extracorporeal bloodstream.

The present invention is solved by a device having the characteristics of claim 1.

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A suitable treatment device is used to perform such a blood treatment.

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The extracorporeal blood circulation may be suitable for connection to a patient's vascular system, but it may also be one that supplies extracorporeal blood to the patient's treatment but is not connected to the patient's vascular system.

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The term substitute fluid may also be used to describe, notwithstanding its name, another fluid which is also a fluid and which is also of use in accordance with the invention.

The device of the invention comprises the step of introducing or entering liquid into the extracorporeal bloodstream, preferably by operation of the secondary conveyor.

The substitute fluid introduced or introduced into the extracorporeal bloodstream may be transported by the extracorporeal bloodstream by operation of the blood pump and/or secondary supply device.

The substitute fluid, which is supplied to the extracorporeal bloodstream, can displace the patient' s blood from the extracorporeal bloodstream after the blood treatment session from both the arterial and venous extracorporeal bloodstream at the same time.

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Blood in the extracorporeal bloodstream after a blood treatment session is removed from the extracorporeal bloodstream and may be discarded.

Beneficial training of the device in accordance with the invention is the subject of each subclaim.

Although the present description refers in various places to a treatment device for dialysis treatment, such as haemodialysis, the present invention is by no means limited to this device for removing blood from an extracorporeal circulation after dialysis treatment.

Rather, the device of the invention for removing or displacing blood from any extracorporeal blood circulation is suitable for use in a wide variety of extracorporeal blood treatments or all extracorporeal blood treatments.

The extracorporeal blood circulation may preferably be connected to the patient' s vascular system by a so-called double needle access or a so-called single needle access.

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Although this description is an example of a DoubleNeedle access, it is not limited to such a design.

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In a preferred embodiment, blood is pumped from the extracorporeal bloodstream by simultaneous operation of the blood pump and the secondary supply device.

Preferably, blood can be supplied from both the arterial and venous portions of the extracorporeal circulation at the same time and with equal relative progress.

Alternatively, however, blood may be transported simultaneously, but with different relative progression, from both the arterial and venous portions of the extracorporeal circulation.

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The uniform progression of blood in differently designed sections of the line may be achieved, for example, by different rotational speeds of the conveying devices; the uniform progression may also be achieved, for example, by the quantity and position of the substitute fluid in the train order and the like.

The arterial and/or venous section of the extracorporeal blood supply may be connected to a patient during the unused procedure, as described above, by double needle or single needle access.

Preferably, the blood displaced from the extracorporeal bloodstream can be essentially or completely returned to the patient's vascular system. e.g. in the case of single needle access, the blood can be re-injected or re-injected into the patient's vascular system via a common access.

In an unused procedure, the blood is pumped until a phase boundary or mixing range between blood and substitute fluid reaches a detection device located in or on a section of the extracorporeal circulation of the treatment device.

The detection device may preferably be designed and intended to detect a qualitative change in the contents of the (inner) extracorporeal blood stream.

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The procedure that is not used can preferably be terminated when the detection device detects, for example, the occurrence of the phase limit or the mixing range between blood and the substitute fluid.

In particular, it may be advantageous to place a first detector in the arterial conduction section and a second detector in the venous conduction section. The two detectors may, for example, be located and designed at or at such a distance from the patient's access point, for example, the arterial or venous connecting needle, such that when the detector detects the presence of a phase boundary or a mixture between blood and substitute fluid, the blood has been essentially drawn back into the patient's circulatory system from the extracorporeal blood supply.

In an unused procedure, the blood pump's conveyor power or conveyor rate shall be controlled or regulated by taking into account at least one parameter relating to the extracorporeal circulation and/or a conveyor power or conveyor rate of the second conveyor.

The blood pump's transfer power or transfer rate can be adjusted, for example, by controlling or regulating a rotational speed of the blood pump.

The second-converter's transfer power or transfer rate may be a predetermined value or values, for example, stored in an appropriate facility in the extracorporeal or circulatory blood and readable and/or continuously recorded and used, preferably in real time, to dynamically control or regulate the transfer power or transfer rate of the blood pump.

Alternatively or in addition, another embodiment of the invention provides for the control or regulation of a secondary conveyor or a secondary rate of conveyance, taking into account at least one parameter relating to the extracorporeal blood circulation and/or a secondary power or a blood pump.

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In a more preferred embodiment, a predetermined amount of substitute fluid is introduced into the intra-corporeal bloodstream by operation of the secondary conveyor.

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The amount of substitute liquid may preferably be, for example, deposited and/or depositable in a control facility.

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This may be a warning signal when air is detected in the arterial line section, and may be used to stop blood flow and/or take other measures.

In this situation, it is particularly possible to correct the error that led to the air infusion, either automatically or by personnel or the user.

This allows the amount of air entering and the volume of blood foam potentially produced to be advantageously minimised by rapid intervention.

Alternatively or in addition, when detecting air leakage or issuing an alert for detected air leakage, an arterial line section may be air removed, hereinafter referred to as arterial air removed, the procedure used, which is not applied, may be equivalent to venous air removed.

Arterial airway removal may differ in its application to online and standard treatment: Other In the online treatment, the patient is arterially disconnected and an external container, e.g. a NaCl bag, is connected to the patient's arterial tube instead of the patient. Substitute from the hydraulics or another source is then, preferably after appropriate safety checks, fed via the substitution pump to the arterial line section of the tube system via the predilution valve. This is done in such a way that the air there is pushed into the connected container. This is also shown in Figure 3. If the tube is empty of air, the patient's container is disconnected and the patient's system is reconnected to the arterial line or cut off. In this way, the patient's blood/air pores remain open and do not enter the external system.

In HD treatment (haemodialysis), however, air removal may also occur as follows: when air is detected, the patient is disconnected both arterially and venously. Both patient tubes or line sections are connected to a container - preferably the NaCl bag mentioned earlier - or to several containers. Then, preferably after prior safety checks, the contents of the container, e.g. NaCl, are reabsorbed into the venous blood vessel or venous valve by the blood pump by reverse pump, and the patient's venous blood vessel or venous valve is thus reabsorbed into the venous blood vessel. This also reveals that the blood vessel is not connected to the venous system (or to the venous system) and that the patient's venous blood vessel is not connected to the venous system (or to the venous system) by an external source of air.

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If the ABD and the corresponding controller detect arterial air, an arterial air alarm is triggered. This can lead to or consist of the immediate closure of the arterial patient's tube plug and/or the cessation of blood supply.

Preferably, the patient is checked by means of the ABD and the appropriate controls to ensure that there is no air in the respective tube section, thus avoiding the need to infuse the patient with air.

The following unused procedure can be used: if a flow reversal is requested by the user (or automatically), a defined volume (preferably at least the volume of the blood system behind the respective ABD) is first transferred to the previous flow direction with the air warning activated, before the actual flow direction reversal is performed or initiated. This should preferably only be allowed if the entire flow volume has been transferred without air warning. Preferably the user has no possibility of manipulating or intervening between the air flow and the flow direction reversal.

The ABD in the arterial thigh also allows for simultaneous reinfusion as described below, preferably to allow switching between pre- and post-dilution without additional user action such as switching the connector.

In the case of simultaneous pure infusion, both connecting needles remain in the patient's vascular system, and the blood is pushed into the venous part of the tube system by means of a substitute pump through the predilution sport until the venous optical detector no longer detects blood.

Preferably, the blood pump should run backwards at the same time, preferably at a very low rate or speed.

The blood supply is controlled by volume control, preferably by using an optical sensor (OD) contained in the ABD. The blood supply is controlled by volume control.

In this procedure, which is not used, preferably only the blood pump can be stopped if an arterial air alarm occurs, and the venous perfusion can be continued.

In certain unclaimed procedures, the return of blood or the reinfusion of blood from the extracorporeal bloodstream after termination of the blood treatment involves the use of a coagulant trapper, which is or is designed according to the invention to be passed through blood which is supplied to the patient by the extracorporeal bloodstream or otherwise removed from the extracorporeal bloodstream by means of the arterial trapper.

The clot trapper can be manually inserted into a corresponding blood-carrying arterial section of the extracorporeal bloodstream in some embodiments of the invention, for example between a section of the arterial line section and the arterial connecting needle, for example between a particularly originally existing tube-end of the arterial line section and a particularly originally existing end of the flexible tube-section of the arterial connecting needle, for example after simple, usual dissection of the arterial light-carrying section from the flexible tube-section of the arterial connecting needle.

The use of the clot holder in some embodiments of the invention involves one or more of the following steps: (a) The clot holder, which may first have to be removed from a sterile packaging, is filled with an appropriate liquid, preferably a saline solution, if this is not already the case. (b) The infusion and/or blood supply through the blood pump is interrupted by appropriate control of the treatment device. This is done in some embodiments of the invention by using a soft key of the treatment device. (c) At the end of the arterial line section and at the end of the arterial line section of the blood vessel (the area in which it is located) the blood flow is interrupted by means of a blood flow, which can be separated by means of two arterial lines and the arterial line section of the blood vessel.(f) If present, the two patient tube clamps (one at the tube of the arterial needle and one at the arterial needle) are opened. In any case, the interrupted blood flow is restored. (g) The reinfusion and/or blood supply through the blood pump, which has been temporarily interrupted, is restarted. This may be done, for example, by means of a soft key on the treatment device. (h) In the invention, the means of treatment are first introduced at the same time, pre-determined by volume, and then the first line of blood supply is introduced at the same time with the two forms of treatment.Patient lines are open.

The order of the steps (a) to (h) above may be varied according to what is possible for the professional to recognize.

The clot trapper according to the invention has a mesh size of preferably 10 to 200 micrometres (μm) and any intermediate values in this range in certain embodiments of the invention.

The task of the invention is solved by a treatment device as claimed in claim 1.The benefits obtained by the unused process are also undiminished by the treatment device of the invention.

The treatment device according to the invention shall have at least an extracorporeal blood circulation, comprising an arterial and a venous section, at least a conveyor to introduce and/or convey fluid into the extracorporeal blood circulation, and at least a control or control device suitable and intended to perform or operate, or control or regulate, the unused procedure.

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In addition, the treatment device according to the invention shall have at least a second conveyor to introduce at least one substitute fluid into the inner tube of the extracorporeal bloodstream to its inner tube conveyors. The second conveyor may be a peristaltic pump, e.g. a tube pump or a roller pump. However, another type of pump, e.g. a membrane pump, in particular a high-precision dosing membrane pump, may also be used.

The second conveyor may have pipes, such as a substitute fluid line, to various storage facilities, such as substitute fluid storage facilities or storage tanks with substitute fluid.

The second conveyor may also have at least a control or control device allowing and/or providing for the automatic introduction and/or conveying of at least one substitute fluid, for example a predetermined amount of substitute fluid.

The second conveyor and its components, in particular its conduits to the extracorporeal bloodstream, shall preferably be part of the extracorporeal blood treatment tube or system and may be intended for or in the extracorporeal bloodstream and may in particular be connected to it by appropriate means, such as by means of clamps, connecting brackets or the like.

The second conveyor may alternatively be located within the extracorporeal bloodstream, and the second conveyor may absorb substitute fluid, e.g. via the substitute fluid line.

A substitute line or substitute fluid line is preferably a supply line that can be connected from a substitute source or substitute fluid storage device. The substitute line may be part or accessory of a tubing set for extracorporeal blood treatment. However, it may also be designed so that it is not directly part of the extracorporeal blood circulation in the sense that no blood flows through the substitute line.

The treatment device of the invention may also include, for example, a treatment device for the treatment of the patient's blood, such as one or more blood filters and/or one or more dialyzers, such as a haemodialyser, and/or one or more absorbers or adsorbers.

The treatment device may also contain containers for storing fluids, fluid delivery elements such as tube elements and/or valves, and additional devices such as a drip chamber to remove air from the blood during the blood treatment and/or sensors and/or detectors to detect various relevant parameters such as extracorporeal blood pressure.

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The treatment device according to the invention may have at least such an external functional device, preferably in the form of such a blood cassette.

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In a preferred embodiment, the treatment device shall have at least one control or control device that is capable of and designed (configured) to control or regulate a blood pump and/or secondary pump supply or supply rate, taking into account at least one parameter relating to extracorporeal circulation.

The parameter, such as data or information in the form of parameters or properties concerning extracorporeal circulation, may be selected from parameters relating to an internal volume of the arterial section of the extracorporeal blood, parameters relating to an internal volume of the venous section of the extracorporeal blood, parameters relating to a supply order for the substitute fluid, such as the location of a pre-dilusion supply order for the substitute fluid and/or the location of a post-dilusion supply order for the substitute fluid, and/or parameters relating to the second-directional supply or supply rate, but not limited to the examples above.

In another preferred embodiment, the treatment device may have at least one storage device in which the extracorporeal circulation parameter can be stored or deposited.

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The treatment device may have at least one input device by which the parameter can be stored in a storage device.

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The input of the parameter may be done by a user, for example manually by typing into a keyboard, or the parameter may be stored in the storage device by transmission from an external storage medium and/or another storage device, for example via an IR interface, Bluetooth, USB port, firewire, SATA and the like, to the treatment device.

Once the parameter has been entered or stored in the storage device, it can be stored permanently, but it can also be stored only for the duration of a treatment session and, for example, temporarily.

In another preferred embodiment, the storage device is suitable and designed or configured to store parameters of different and even different extracorporeal circulation, e.g. the data stored for the tubal system or the blood tube set used in a treatment session can be selected before treatment.

This may be particularly advantageous if different or different types or systems or arrangements of extracorporeal circulation or of tubal systems are to be used in or on a treatment device.

In a more preferred embodiment, the storage device may be located on or in at least one section of the extracorporeal bloodstream. For example, the storage device may be in the form of a barcode and/or 2D (dot matrix) code and/or RFID chip. The treatment device may, for example, automatically read data or parameters and provide them to the control or controlling device. It may be located, for example, in the tubal system, e.g. in the arterial and/or venous conduction section of the extracorporeal bloodstream.

The storage device may be provided on or in an external functional device, such as the blood cartridge mentioned above, which may contain, for example, the specifications of the individual components or sections of the blood cartridge as determined during the manufacture of the blood cartridge.

If the storage device is intended to be an external storage device, the treatment device may preferably also have at least one receiving device and/or at least one reading device that is suitable and designed to receive and read the external storage device.

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For example, a suitable external storage device may also be provided in or on a patient card, for example in the form of a chip.

The read-out or read-out parameters may be transmitted to a central processor of a control or control unit of the treatment device and used, for example, to control or regulate the blood pump's propulsion power or propulsion rate.

In certain embodiments of the invention, the treatment device has an extracorporeal blood circulation.

The device of the invention allows blood which is in an extracorporeal blood circulation of the treatment device after a blood treatment session to be removed from both the arterial and venous portions of the extracorporeal blood circulation at a favourable rate.

In particular, it may prevent clot formation in the patient's vascular system, or at least reduce the risk of such formation.

The treatment device of the invention may be capable of automatically calculating, by means of the control device, the required rate or rate of delivery of the blood pump or other delivery device, and of controlling the blood pump or other delivery device accordingly, on the basis of data on the internal volumes of all or some sections of the blood tube, taking into account, where appropriate, the position of the selected drainage order for the substitute and/or the specified rate or delivery capacity of the substitute pump, so as to allow simultaneous displacement of blood from the usually different volumes of the arterial and venous line section in the patient.

The blood pump or other conveyor can be controlled in a particularly advantageous way, so that the blood supply can be returned not only simultaneously but also at the same speed. According to the invention, this can be advantageous in completing the removal of blood from both lines of the extracorporeal bloodstream at the same time. This can save time and cost in a particularly advantageous way.

Since blood can be returned to the patient' s vascular system from both lines simultaneously and with equal progress, unnecessary or unwanted infusion of replacement fluid into the patient' s vascular system after blood treatment has been completed can be avoided.

Since the blood is essentially completely removed from the extracorporeal bloodstream and the extracorporeal bloodstream can be flushed with substitute fluid at the same time, the risk of contamination of others or the environment with the patient' s blood can be beneficially reduced, particularly for the disposal of the extracorporeal bloodstream after the end of treatment.

The present invention is described below by reference to the preferred embodiments of the invention, and in the drawing, identical reference marks refer to the same or identical elements. Figure 1 shows a schematic overview of an exemplary treatment device according to the invention for performing the procedure without application of stress;Figure 2 shows a simplified schematic of a stage during the execution of a procedure according to the invention without application of stress; andFigure 3 shows a basic outline of an extracorporeal blood system with arterial ABD (Air Bubble Detector).

For illustrative purposes of the present invention, a blood treatment device, e.g. a haemodialysis device, is selected as the treatment device. It is expressly noted that the drainage of the extracorporeal blood stream can also be performed according to the invention without the drained blood being returned to the patient.

The normal arrows in Figure 2 show one direction of blood flow, and the block arrows show one direction of the substitute flow.

In Fig. 1 an extracorporeal blood circulation 1000 of a treatment device 2000 according to the invention is shown with a DoubleNeedle access to the vascular system of a patient 3000.

The arterial line section 1 is connected to the vascular system of patient 3000 via an arterial patient access, e.g. as shown in Figure 1, in the form of an arterial connecting needle 5, and the venous line section 3 is connected to the vascular system of patient 3000 via a venous patient access, e.g. as shown in Figure 1, in the form of a venous connecting needle 7,

The arterial line section 1 has an arterial patient tube clamp 9 and the venous line section 3 has a venous patient tube clamp 11.

The extracorporeal blood circulation 1000 has a blood pump 13 The blood pump 13 is designed as a rolling pump The blood pump 13 carries the blood of the patient 3000 through the extracorporeal blood circulation 1000

The extracorporeal circulation 1000 has a blood treatment device 15, such as a haemodialyser.

As shown in Fig. 1, in the arterial line section 1, an arterial pressure sensor 17 is located downstream (relative to the usual direction of supply during a blood treatment) from the blood pump 13.

In the venous line section 3, a venous drip chamber 19 and a venous pressure sensor 21 are located upstream of the venous drip chamber 19.

By means of a secondary conveyor, e.g. a substitution pump 23, substitute fluid from a substitution fluid storage device 25 can be introduced into the extracorporeal bloodstream 1000 via a substitution fluid line 27 to a pre-dilusion line 29 for substitution fluid and/or a post-dilusion line 31 for substitution fluid.

The treatment device 2000 has a control or control device 33; the control device 33 is connected to the blood pump 13 by a control line 35 and to the replacement pump 23 by a control line 37; however, it may be sufficient to provide only one control or control line, either to the blood pump 13 or to the replacement pump 23, to perform the procedure that is not being used.

The control device 33 may, for example, control a rate or rate of blood pump 13 depending on the operating parameters of the substitute pump 23, such as its rate or rate of blood pump 23.

The control lines 35 and 37 may allow bi-directional communication between the control device 33 and the blood pump 13 or the substitution pump 23.

Figure 1 shows a connection of the blood treatment device 2000 according to the invention with the vascular system of the patient.

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Figure 2 shows a stage of an unused procedure to remove blood from the extracorporeal bloodstream 1000 after completion of a blood treatment in a special embodiment in which the blood is returned to the patient's vascular system.

Both the arterial patient tube clamps 9 and the venous patient tube clamps 11 are in an open and open state, respectively.

Blood pump 13 and replacement pump 23 are operational.

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During the unused procedure, the blood pump 13 rotates clockwise and thus against the usual direction of supply during a blood treatment (patient - arterial line section - blood treatment device - venous line section - patient).

The substitute pump 23 is rotating counterclockwise.

The rotation speeds of the blood pump 13 and the replacement pump 23 may be different from each other. The rotation speeds of the blood pump 13 and the replacement pump 23 may be identical. The blood pump 13 and the replacement pump 23 may be started at the same time and/or rotated for the same (set) duration. The blood pump 13 and the replacement pump 23 may be rotated at different times and/or for different (set) durations.

Blood is in the extracorporeal circulation 1000 (simply marked area) and substitute fluid is introduced via the substitute fluid line 27 (cross-shaped marked area in Figure 2).

A pre-dilutions inlet valve 291 of the pre-dilutions inlet 29 is open; alternatively or additionally a post-dilutions inlet valve 311 of the post-dilutions inlet 31 may be open; however, in the figure 2 the post-dilutions inlet valve 311 of the post-dilutions inlet 31 is closed.

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The predilusion valve 291 allows substitute fluid to enter the extracorporeal bloodstream 1000.

Figure 2 shows the configuration of the blood treatment device 2000 in a snapshot during the blood drain or blood return process, where the substitute fluid is introduced upstream (relative to the usual direction of supply during a blood treatment) into the extracorporeal bloodstream 1000 by the open predilution drain valve 291.

The substitute fluid can displace blood between the predilusion valve 291 and the venous connecting needle 7, i. e. blood upstream of the predilusion valve 291 in the arterial line section 1 and blood in the venous line section 3.

The displaced blood can be returned to the patient' s vascular system through the venous connecting needle 7.

The replacement fluid is conveyed upstream from the predilusion valve 291 through the treatment facility 15 and the venous line section 3 to patient 3000 via the arterial line section 1 of the extracorporeal bloodstream 1000.

At the same time, blood in the extracorporeal circulation 1000 is transported forward and downstream of the predilution valve 291 through the arterial line section 1 to patient 3000.

The substitute fluid is introduced from the pre-dilusion intake valve 291 into the arterial line section 1 arranged downstream from the pre-dilusion intake valve 291 and is conveyed towards patient 3000.

The simultaneous drainage of blood from the arterial line section 1 of the extracorporeal bloodstream 1000 and the venous line section 3 of the extracorporeal bloodstream 1000 may, as desired, be carried out with equal progress, i.e. the extent of drainage (e.g. as a percentage of line content) of blood still in each of the line sections 1 and 3 may be identical at any time.

The drainage or return of blood from the extracorporeal blood stream 1000 can be stopped at the same time, for example, just before the replacement fluid reaches the arterial connecting needle 5 and just before the replacement fluid reaches the venous connecting needle 7, the blood pump 13 and the replacement pump 23 can be stopped.

Alternatively, the replacement fluid can be introduced into the extracorporeal bloodstream 1000 either additionally or through the post-dilution intake valve 311 as mentioned above.

However, the method used to perform the procedure not claimed is essentially the same as that described above for the substitute liquid added by pre-dilution, so that reference is made to the above.

Figure 3 shows a basic outline of an extracorporeal blood system with arterial ABD (Air Bubble Detector) or air detector for performing procedures that are not required. The components shown are essentially already known from Figures 1 and 2.

The direction of the pump, indicated by the crossed arrows, corresponds to the regular or forward directions; the direction of the pump, indicated by the dashed lines, corresponds to its reverse direction or to its absorption by the pump.

Claims (14)

1. Treatment apparatus (2000) comprising:

   - at least one device for receiving at least one extracorporeal blood circuit (1000), including an arterial conduit portion (1) having a conduit interior and a venous conduit portion (3) having a conduit interior;

   - at least one blood pump (13) arranged on or in the extracorporeal blood circuit (1000) for conveying blood within the extracorporeal blood circuit (1000);

   - at least one second conveying means for introducing at least one liquid into the extracorporeal blood circuit (1000) and/or for conveying the liquid in the extracorporeal blood circuit (1000);

   characterized by:

   - at least one control or regulating device (33) suitable and provided for carrying out a method for removing blood after finishing a blood treatment session comprising the steps of:

   - introducing liquid into the extracorporeal blood circuit (1000);

   - conveying the fluid for simultaneously discharging blood from both the arterial conduit portion (1) and the venous conduit portion (3) of the extracorporeal blood circuit (1000).
2. The treatment apparatus (2000) according to claim 1, wherein blood is conveyed from the extracorporeal blood circuit (1000) while simultaneously operating of the blood pump (13) and the second conveying means.
3. The treatment apparatus (2000) according to claim 1 or 2, wherein blood is conveyed with equal velocity relative progress from both the arterial conduit portion (1) and the venous conduit portion (3) of the extracorporeal blood circuit (1000).
4. The treatment apparatus (2000) according to claim 1 or 2, wherein blood is conveyed at different relative progress from both the arterial conduit portion (1) and the venous conduit portion (3) of the extracorporeal blood circuit (1000).
5. The treatment apparatus (2000) according to anyone of the preceding claims, which comprises at least one detection means arranged in a portion of the extracorporeal blood circuit (1000) for detecting a qualitative change in the content of the extracorporeal blood circuit, the method comprising the steps of:

   - conveying blood, until a phase boundary or a mixing region between blood and liquid is detected by the detection device; and

   - terminating conveyance of blood upon detection of the phase boundary or of the mixing region by the detection means.
6. The treatment apparatus (2000) according to anyone of the preceding claims comprising at least one control or regulating device (33) suited and provided for controlling or regulating a conveying capacity or conveying rate of the blood pump (13) and/or of the second conveying means, under consideration of at least one parameter relating to the extracorporeal blood circuit (1000).
7. The treatment apparatus (2000) according to claim 6, wherein the parameter relating to the extracorporeal blood circuit (1000) is selected from parameters relating to an inner volume of the arterial conduit portion (1) of the extracorporeal blood circuit (1000), parameters relating to an inner volume of the venous conduit portion (3) of the extracorporeal blood circuit (1000), parameters relating to an addition point for a substituate liquid, such as the position of a pre-dilution addition point (29) for the substituate liquid and/or the position of a post-dilution addition point (31) for the substituate liquid, and/or parameters relating to the conveying capacity or the conveying rate of the second conveying means.
8. The treatment apparatus (2000) according to anyone of claims 6 to 7, wherein the treatment apparatus (2000) further comprises at least one memory means designed and intended to store the parameter.
9. The treatment apparatus (2000) according to anyone of claims 6 to 8, wherein the treatment apparatus (2000) further comprises at least one input means whereby the parameter may be deposited in a memory means.
10. The treatment apparatus (2000) according to anyone of claims 1 to 9, wherein the treatment apparatus (2000) further comprises at least one external functional device, in particular a blood cassette (4000).
11. The treatment apparatus (2000) according to anyone of claims 1 to 10, wherein the treatment apparatus (2000) is a dialysis apparatus or a hemodialysis apparatus.
12. The treatment apparatus (2000) according to anyone of claims 1 to 11, wherein the blood pump (13) is designed as a roller pump.
13. The treatment apparatus (2000) according to anyone of claims 1 to 12, wherein the second conveying means is designed as a roller pump.
14. The treatment apparatus (2000) according to anyone of claims 1 to 13 comprising at least one extracorporeal blood circuit (1000).