Method and device for controlling a blood treatment device

Abstract

The present invention relates to a method for controlling a blood treatment device (100) when an air bubble or air pocket detected by an air bubble detector (315) is present in an extracorporeal blood circuit (300) connected to the blood treatment device (100).The present invention also relates to an open-loop or closed-loop control device (150) and a blood treatment device (100), a digital storage medium, a computer program product, and a computer program for implementing the method according to the invention.

Description

[Technical Field]

[0001] The present invention relates to a method for controlling a blood treatment apparatus as described in claim 1, a control device or closed-loop control device as described in claim 9, and a blood treatment apparatus as described in claim 10. Furthermore, the present invention relates to a digital storage medium as described in claim 15, a computer program product as described in claim 16, and a computer program as described in claim 17, or any of the general or generic terms of these claims. [Background technology]

[0002] In practice, various types of blood treatment devices are known. These include, for example, devices for hemodialysis, hemofiltration, and hemodiafiltration. During extracorporeal blood treatment, blood flows through an extracorporeal blood circuit and passes through a blood treatment unit. In devices for hemodialysis, hemofiltration, and hemodiafiltration, the blood treatment unit is, simply put, a dialyzer or filter separated into a blood chamber and a dialysate chamber by a semipermeable membrane. During blood treatment by hemodialysis or hemodiafiltration, blood flows through the blood chamber and dialysate flows through the dialysate chamber.

[0003] Gas bubbles or microbubbles in the extracorporeal circuit downstream of the venous air separation chamber can cause gas embolism in the patient's body. Embolism can block blood vessels and cause ischemia. To prevent gas from entering the patient's vascular system during dialysis, the venous air separation chamber is positioned within the venous blood tubing system. It partially reduces the flow velocity in the extracorporeal circuit, thereby allowing gas bubbles to rise against gravity according to Archimedes' principle and be separated through the opening in the upper region of the venous air separation chamber.

[0004] Furthermore, the venous system downstream of the air separation chamber is monitored by a bubble detector for the presence of air in the blood flowing outside the body, for example, in the form of microbubbles. If the sensor detects the presence of air, a bubble alarm is issued, and the patient's blood procedure is interrupted. Once the cause of the bubble alarm is corrected by the staff, the blood procedure can be resumed. [Overview of the project]

[0005] The object of the present invention is to propose a method for controlling or adjusting a blood treatment device after detecting such air bubbles in an extracorporeal blood circuit. Furthermore, a control device or closed-loop control device (abbreviated as: control device, which can also be optionally adjusted) is proposed, and the method may be carried out, initiated, or implemented using it. Further devices suitable for carrying out the method, in particular blood treatment devices, digital storage media, computer program products, and computer programs are specified.

[0006] The object of the present invention is achieved by a method having the features of claim 1. Furthermore, it is achieved by a control device or closed-loop control device having the features of claim 9, a blood treatment device having the features of claim 10, a digital storage medium having the features of claim 15, a computer program product having the features of claim 16, and a computer program having the features of claim 17.

[0007] Accordingly, the present invention proposes a method for controlling a blood treatment device, wherein the blood treatment device comprises a blood pump, a bubble detector, and a pump for transporting the dialysis fluid and / or dialysis fluid on the hydraulic side. The method is initiated or performed during an extracorporeal blood treatment session in which the blood treatment device is connected to an extracorporeal blood circuit and a blood filter comprising a semipermeable membrane.

[0008] Here, for example, when air bubbles or air pockets are detected in the extracorporeal blood circuit, or when an air bubble alarm is triggered, the method includes stopping the blood pump or reducing the transport speed that was being used immediately before the detection of air, and generating a negative intermembrane pressure difference across the semipermeable membrane of the blood filter.

[0009] This negative intermembrane pressure difference can be achieved by appropriately controlling the hydraulic pump while the blood pump is stopped or its transport speed is reduced.

[0010] The intermembrane pressure difference may be measured directly or indirectly by various methods, or its presence may be detected.

[0011] Detection of bubbles or air pockets in an extracorporeal blood circuit can be achieved using a bubble detector. The bubble detector may also be suitable, or configured, to trigger a bubble alarm (or alternatively, a gas alarm) as a result of detecting gas, air, or bubbles, and the alarm will initiate or carry out the method according to the present invention.

[0012] Bubbles or air pockets can be detected, for example, by a bubble alarm, when the conditions that trigger the bubble alarm or conditions that are sufficient to trigger the bubble alarm are met.

[0013] According to the present invention, a control device or closed-loop control device is further proposed, configured to interact with a blood treatment device or its device or apparatus, particularly automatically, to initiate, perform, control, and / or adjust the method according to the present invention.

[0014] An interaction may be, or may include, actuation, control, or regulation. An interaction may be, or may require, a signal connection.

[0015] According to the present invention, a blood treatment apparatus is further proposed comprising, or connected to, at least, a blood pump, a bubble detector, a pump for transporting dialysate and / or dialysate, and a control device or closed-loop control device, in particular, a control device or closed-loop control device according to the present invention configured to initiate the implementation of the method according to the present invention.

[0016] For each of the steps of the method according to the present invention as described herein, the blood treatment apparatus according to the present invention may have, or be connected to, a correspondingly suitable and / or configured device or apparatus, such as a pressure measuring device for measuring pressure, etc.

[0017] The digital, in particular non-volatile, storage medium (also referred to herein as a carrier) according to the present invention, having in particular electronically or optically readable control signals, is in the form of a diskette, RAM, ROM, CD, hard disk, DVD, USB stick, flash card, SD card, or EPROM, and can be configured such that a conventional control device becomes a control device or closed-loop control device according to the present invention that can initiate or carry out the methods according to the present invention as described herein. Alternatively or additionally, the digital storage medium can be configured to configure a hematology apparatus to be a hematology apparatus according to the present invention that can perform or carry out the methods according to the present invention as described herein.

[0018] At this point, all, some, or any part of the mechanical induction steps of this method may be initiated.

[0019] The computer program product according to the present invention comprises volatile or temporary program code, or that stored on a machine-readable carrier, which can be configured to a control device or a closed-loop control device capable of starting or implementing the method according to the present invention described herein. Alternatively or additionally, via the computer program product, the blood treatment device can be configured such that the method according to the present invention described herein can be carried out or executed.

[0020] At that time, all, part, or some of the machine-guided steps of the method can be started.

[0021] As used herein, the term "machine-readable carrier" refers, in particular embodiments of the present invention, to a carrier containing data or information interpretable by software and / or hardware. The carrier can be, for example, a data carrier such as a diskette, CD, DVD, USB stick, flash card, SD card, or EPROM.

[0022] The computer program according to the present invention comprises program code configured such that a control device or a closed-loop control device or a blood treatment device can start or implement the method according to the present invention described herein.

[0023] At that time, all, part, or some of the machine-guided steps of the method can be started.

[0024] The computer program product can be understood, for example, according to the present invention, as a computer program stored on a carrier, an embedded system (such as an electronic device having a computer program) which is an integrated system having the computer program, a network of computer programs implemented by a computer (such as a client / server system, a cloud computing system, etc.), or a computer on which the computer program is loaded, operated, stored, executed, or deployed.

[0025] According to the present invention, a computer program can be understood, for example, to mean a physical market-oriented software product comprising the program.

[0026] Throughout the description herein, the use of expressions such as "can be" or "can have" should be understood to be synonymous with, for example, "is preferably" or "preferably has", respectively, and is intended to illustrate an embodiment of the present invention.

[0027] When numerical terms are described herein, those skilled in the art shall always recognize or understand them as indicators of the lower limit values of the numerical values. Unless those skilled in the art are led to an obvious contradiction, those skilled in the art shall understand that a designation such as "one" (similarly "a / an") includes "at least one". This understanding is equally included in the present invention as an interpretation that, when the numerical term, for example, "one" (similarly "a / an") is clearly technically possible for those skilled in the art, it may alternatively mean "exactly one". Both understandings are included in the present invention and apply to all numerical terms used herein.

[0028] The terms "programmed" or "configured" are always disclosed to be interchangeable with each other when described herein.

[0029] When the present specification refers to a venous air separation chamber or, for short, an air separation chamber, it may be a venous blood chamber, a venous air bubble chamber, or a venous drip chamber.

[0030] Each further advantageous development of the present invention is the subject of the dependent claims and embodiments.

[0031] When an embodiment is described herein, it always represents an exemplary embodiment of the present invention.

[0032] Where it is disclosed herein that the subject matter of the present invention has one or more features in a particular embodiment, it is also disclosed herein that the subject matter of the present invention may not expressly have one or more of those features in other embodiments of the same invention, for example, as a disclaimer. Therefore, it applies to all embodiments described herein that reverse embodiments, for example formulated as negatives, are also disclosed.

[0033] Embodiments of the present invention may include one or more of the above and / or below features in any technically possible combination.

[0034] In some embodiments of the method according to the present invention, generating a negative intermembrane pressure difference across a semipermeable membrane is performed with the venous tube clamp fully or partially closed.

[0035] In some embodiments, the method further comprises opening the venous tube clamp while maintaining a negative intermembrane pressure difference, when a negative intermembrane pressure difference has already been generated or exists.

[0036] Due to a negative intermembrane pressure difference, (transmembrane) plasma water transfer occurs across the semipermeable membrane, and the blood in the dialyzer becomes hemoconcentrated. As a result, the amount of fluid that is pumped into the hydraulic system or shifted to the hydraulic side from the extracorporeal blood circuit across the semipermeable membrane due to the pressure difference is replaced by blood flowing from the latter and from the patient's vascular system through the venous portion of the tubing system in the opposite direction to the normal flow within the blood circuit (also referred to herein as retrograde flow), due to hemoconcentration and negative pressure. Consequently, air bubbles or air pockets in the line (e.g., gas bubbles and microbubbles) are transported back in the retrograde flow to the venous air separation chamber, where they are separated and mostly released into the environment.

[0037] In some embodiments of this method, the venous tube clamp is opened when the pressure sensor of the blood treatment device detects that a negative minimum intermembrane pressure difference has been reached.

[0038] In some embodiments, a negative intermembrane pressure difference is generated by the hydraulic pump of the hemotherapy device while an optional replacement pump of the hemotherapy device is stopped or not transporting blood.

[0039] In some embodiments of this method, the generation or maintenance of a negative intermembrane pressure difference is terminated when a negative intermembrane pressure difference of approximately -300 mmHg to -500 mmHg is reached, or when the generated intermembrane pressure difference causes at least 30 to 60 ml of blood to pass through the bubble detector and be transported toward the venous air separation chamber.

[0040] In some embodiments, the transport by the hydraulic pump on the hemotherapy device to generate a negative intermembrane pressure difference is terminated after the bubble detector no longer detects bubbles or air pockets, and / or after the bubble alarm has stopped, and / or after at least 30-60 ml of blood has been transported in the reverse direction.

[0041] In some embodiments, the pump for transporting the dialysate and / or the dialysate is an optionally provided ultrafiltration pump.

[0042] In some embodiments, the blood treatment device according to the present invention is connected to an extracorporeal blood circuit and a blood filter, wherein the blood filter comprises a semipermeable membrane.

[0043] In some embodiments, the extracorporeal blood circuit is a blood tube set and / or blood cassette, or comprises a blood tube set and / or blood cassette.

[0044] In some embodiments of the blood treatment device, the pump for transporting the dialysate and / or dialysate is an ultrafiltration pump.

[0045] In some embodiments, the blood treatment device is embodied as a hemodialysis device, a hemofiltration device, a hemodiafiltration device, or a device for performing separation procedures.

[0046] In some embodiments of this method, this involves determining whether the generated negative intermembrane pressure difference or its absolute value is within a predetermined limit, whether it exceeds or falls below a threshold, whether it exceeds a minimum value, and / or does not exceed a maximum value. This can be done based on at least one criterion (such as a threshold, range, or maximum value) which may be stored in a memory device, such as a blood treatment device.

[0047] In some embodiments, the method comprises emitting or outputting an audible and / or optical or otherwise signal-linked bubble alarm only if, during or after the process of the method according to the present invention, conditions still exist or re-exist that should have already resulted in a bubble alarm to the person in charge and / or the blood treatment device before the commencement of the method according to the present invention. Thus, it may be provided that, after a bubble is detected, the presence of a bubble alarm is optically and / or acoustically notified to the user, and / or the blood treatment is automatically interrupted, only if the removal of the detected air by the method according to the present invention, for example, the features of claim 1, is unsuccessful.

[0048] In some embodiments, the pump is a positive displacement pump, particularly a diaphragm pump, an eccentric diaphragm pump, a peristaltic pump, a roller pump, or a piston pump.

[0049] When this specification refers to a signaling or communication connection between two components, it should be understood to mean a connection that exists at the time of use.

[0050] In some embodiments, the extracorporeal blood circuit does not include a venous air isolation chamber that is inverted or upside down, or a venous air isolation chamber in which the narrower end (or end with a smaller diameter or cross-sectional area) of the air isolation chamber is higher than the wider end (or end with a larger diameter or cross-sectional area).

[0051] In some embodiments, a negative intermembrane pressure difference is not applied to remove air bubbles directly from the air separation chamber and thus from the extracorporeal blood circuit, bypassing the blood filter.

[0052] In some embodiments, this method is not a method for draining fluid from a device for extracorporeal blood treatment.

[0053] In some embodiments, a negative intermembrane pressure difference is applied while the blood pump is stopped and / or not transporting blood.

[0054] Several embodiments of the present invention can achieve one or more of the advantages described herein, including the following:

[0055] The method according to the present invention advantageously avoids procedures that require considerable effort from the user. Conventionally, the user must disconnect the venous side from the patient, which requires the hygienically important disconnection of at least one tubing segment filled with whole blood, and then connect the venous tubing system to a saline bag to pump the detected volume of blood in the venous line containing air bubbles or air pockets at a low flow rate to, for example, a saline bag. In this conventional method, once the user recognizes that there is no more gas in the line, they reconnect the venous line to the patient and continue the procedure. In clinical practice, these actions have sometimes been ignored due to the time-consuming nature of dealing with air bubble alarms during dialysis, and the patient was at risk of gas embolism. Therefore, the present invention can simplify the procedure and enhance patient safety.

[0056] A further advantage of the present invention is that the patient may not suffer blood loss during the method according to the present invention, such as by discarding whole blood into the aforementioned saline bag. This also advantageously contributes to patient comfort and patient safety.

[0057] The present invention may provide a fully automated and hygienically sound method for addressing bubble alarms in intravenous lines, involving the induced separation of microbubbles. This can, advantageously, help reduce personnel effort and enhance patient safety.

[0058] The present invention will be described below based on preferred embodiments with reference to the accompanying drawings. The method and blood treatment apparatus according to the present invention will be described using a hemodialysis device as an example. However, the method according to the present invention can also be used with other blood treatment devices, such as hemodialysis filtration devices. [Brief explanation of the drawing]

[0059] [Figure 1] A schematic and simplified representation of the fluid line structure of the blood treatment apparatus according to the present invention in the first embodiment is shown. [Figure 2] A simplified schematic representation of a portion of the blood treatment apparatus shown in Figure 1 during the method according to the present invention is provided. [Figure 3] The procedure of the present invention is shown in a simplified manner. [Modes for carrying out the invention]

[0060] Figure 1 shows a schematic and simplified representation of the fluid line structure of the blood treatment device 100 according to the present invention in the first embodiment.

[0061] The blood treatment device 100 is connected to an extracorporeal blood circuit 300, which may be connected to the patient's vascular system (not shown) for treatment using a double-needle access or via a single-needle access using an additional Y connector (reference number Y), as shown in Figure 1, for example. The blood circuit 300 may optionally be located partially on or within a blood cassette.

[0062] The pumps, actuators, and / or valves within the blood circuit 300 are connected to the blood treatment device 100 according to the present invention, or, for example, a control device or closed-loop control device 150 encompassed thereby.

[0063] The blood circuit 300 comprises (or is connected to) a first tube clamp, which is an arterial tube clamp or patient tube clamp 302, and an arterial portion or patient arterial line, arterial side line portion, blood return line, or arterial connecting needle for the first line 301. The blood circuit 300 further comprises (or is connected to) a second tube clamp, which is a patient venous tube clamp 306, and a venous portion, patient venous line, venous side line portion, blood return line, or venous connecting needle for the second line 305.

[0064] A blood pump 101 is provided in or within the first line 301, and a replacement fluid pump 111 is connected to a dialysate inlet line 104 for transporting new dialysate (replacement fluid) filtered in a further filtering stage (F2). A replacement fluid line 105 may be fluidly connected to the inlet line 104. Using the replacement fluid pump 111, the replacement fluid can be introduced into the line portion via the associated line 107a or 109a, for example, into the arterial line portion 301 or the venous line portion 305 (here between the blood chamber 303b of the blood filter 303 and the venous air separation chamber or venous blood chamber 329 of the blood circuit 300) by pre-dilution by pre-dilution by pre-dilution by pre-dilution by pre-dilution by pre-dilution by post

[0065] The blood filter 303 comprises a blood chamber 303b connected to an arterial line portion 301 and a venous line portion 305. The dialysate chamber 303a of the blood filter 303 is connected to a dialysate inlet line 104 leading to the dialysate chamber 303a and a dialysate outlet line 102 leading away from the dialysate chamber 303a, the outlet line 102 carrying dialysate, i.e., used dialysate. For this purpose, suitable connectors can be used on one dialysate inlet line 104 or dialysate outlet line 102 and on the other dialysate port, and in particular, they can be detachably connected to each other.

[0066] The dialysate chamber 303a and the blood chamber 303b are separated from each other by a nearly semipermeable membrane 303c. This represents a partition between the blood side, which has the extracorporeal blood circuit 300, and the machine side, which has the dialysate or dialysate circuit, as shown to the left of the membrane 303c in Figure 1.

[0067] The arrangement shown in Figure 1 preferably includes a bubble detector 315 for detecting air and / or blood, for example, in the position shown in the figure, within the venous line portion 305.

[0068] The configuration shown in Figure 1 may optionally further include one or two pressure sensors PS1 (upstream of the blood pump 101) and PS2 (downstream of the blood pump 101) (to measure the pressure upstream of the blood filter 303 ("prehemofilter")) at the locations shown in Figure 1. Further pressure sensors, such as a pressure sensor PS3 downstream of the venous air separation chamber 329, may be provided.

[0069] In Figure 1, an optional single-needle chamber 317 is used as a buffer and / or compensatory reservoir in a single-needle method in which the patient is connected to an extracorporeal blood circuit 300 using only one of two blood lines 301, 305.

[0070] The configuration shown in Figure 1 also includes an optional detector 319 for detecting air bubbles and / or blood.

[0071] An optional addition site 325 for heparin can be provided.

[0072] On the left side of Figure 1, an optional mixing device 163 is shown, which supplies predetermined mixtures for the respective solutions from container A (for concentrate A via concentrate supply unit 166) and container B (for concentrate B via concentrate supply unit 168) for use by the blood treatment device 100. The solutions contain water from a water supply source 155 (online, for example as reverse osmosis water, or from a bag), which is heated, for example, in an optional heating device 162.

[0073] A pump 171, which may be called a concentrate pump or sodium pump, may be fluidly connected to the mixing device 163 and a sodium supply source, such as container A, and / or transport from there once supplied. An optional pump 173 for, for example, bicarbonate, associated with container B can also be seen.

[0074] Furthermore, Figure 1 shows a waste outlet 153 for drainage. The illustrated configuration is completed by an optional heat exchanger 157 and a first flow pump 159 suitable for degassing.

[0075] To measure the filtrate pressure or membrane pressure of the blood filter 303, an optional pressure sensor PS4 may be provided downstream of the blood filter 303 on the water side, but preferably upstream of the ultrafiltration pump 131 in the dialysate outlet line 102.

[0076] The blood exiting the blood filter 303 flows through a venous air separation chamber 329, which may be equipped with a degassing device 318 and may be in fluid communication with a pressure sensor PS3.

[0077] The exemplary arrangement shown in Figure 1 includes a control device or closed-loop control device 150, which may be wired or wirelessly signaled to any of the components described herein, particularly or specifically to the blood pump 101, in order to control or regulate the blood treatment device 100.

[0078] By using an optional device for online mixing of the dialysate, variations in the sodium content controlled by the control device or closed-loop control device 150 can occur within certain limits. For this purpose, measurements determined by conductivity sensors 163a, 163b may be considered in particular. If it is found that adjustment of the sodium content (sodium concentration) of the dialysate or substitution fluid is necessary or desirable, this can be done by adjusting the transport speed of the sodium pump 171.

[0079] Furthermore, the blood treatment device 100 includes a device for transporting new dialysate and dialysate on the so-called hydraulic side of the blood treatment device 100.

[0080] A first valve may be provided between the first flow pump 159 and the blood filter 303 to open and close the inlet of the blood filter 303 on the inlet side. An optional second flow pump 169 may be provided, for example, downstream of the blood filter 303, to transport the dialysate to the waste outlet 153. A second valve may be provided between the blood filter 303 and the second flow pump 169 to open and close the outlet on the outlet side.

[0081] Furthermore, the blood treatment device 100 optionally includes a device 161 for balancing the flow into or out of the dialyzer 303 on the machine side. The balancing device 161 is preferably located in the line portion between the first flow pump 159 and the second flow pump 169.

[0082] The blood treatment device 100 further includes devices such as an ultrafiltration pump 131 for precisely removing a certain amount of fluid from the balance circuit, as predetermined by the user and / or the control device or closed-loop control device 150.

[0083] Optional conductivity sensors such as 163a and 163b, in some embodiments, serve to determine the temperature-compensated conductivity and the upstream and downstream liquid flow rates of the dialyzer 303.

[0084] The temperature sensors 165a, 165b may be provided as one or more of them. The temperature values ​​supplied by them may be used to determine temperature-compensated conductivity according to the present invention.

[0085] For example, a compressed air source 175 of any choice in the form of a compressor may be provided upstream of the blood filter 303 on the machine side.

[0086] A leak sensor 167 is optionally provided. Alternatively, it may be provided in a different location.

[0087] For example, additional flow pumps may be provided in addition to or as a replacement for the flow pump specified in reference number 169.

[0088] In Figure 1, each of several optional valves is indicated by V. The bypass valve is indicated by VB.

[0089] Based on the measurements from the optional sensors described above, the control device or closed-loop control device 150 determines, in some embodiments, the electrolyte balance and / or fluid balance.

[0090] Filters F1 and F2 may be provided connected in series.

[0091] Even when using non-pure water, filter F1, as exemplary in this specification, functions to produce a dialysate of sufficient purity next to the mixing device 163, which then flows through the blood filter 303, for example, using a countercurrent principle.

[0092] Filter F2, as exemplary in this specification, serves to produce a sterile or well-filtered replacement fluid from the sufficiently pure dialysate that has passed through the first filter F1, for example, by filtering out pyrogenic substances. This replacement fluid can then be safely added to the blood flowing outside the patient's body, thereby ultimately being added to the patient's body.

[0093] The blood treatment device 100 shown in Figure 1 may be a hemofiltration device, a hemodiafiltration device, or a hemodialysis device.

[0094] The present invention is not limited to the above-described embodiments, which are merely illustrative.

[0095] The arrows and arrowheads shown in Figure 1 generally indicate the direction of flow.

[0096] The arterial line portion 301 and the venous line portion 305 may be part of or form part of a blood tube set.

[0097] Figure 2 schematically shows a simplified portion of the blood treatment apparatus 100 in Figure 1, specifically the portion to the right of the dashed line A, during the method according to the present invention.

[0098] To avoid repetition, please refer to the explanation in Figure 1.

[0099] The method according to the present invention, which is described in more detail in Figure 3, creates a reverse flow in the venous line portion 305, as indicated by the reverse direction of the arrows and arrowheads compared to Figure 1. This is done to prevent or significantly reduce the flow between the patient and the venous tube clamp 306, and to move the fluid from the blood chamber 303b to the dialysate chamber 303a, also as indicated by the arrows.

[0100] Figure 3 schematically shows the pathway of the method according to the present invention.

[0101] The blood treatment device 100 controlled by the method according to the present invention comprises a blood pump 101, a bubble detector 315, and a pump for transporting the dialysate and / or dialysate on the hydraulic side of the blood treatment device 100 (see Figures 1 and 2). This method is performed during an extracorporeal blood treatment session, i.e., during dialysis. During this time, the blood treatment device 100 is connected to an extracorporeal blood circuit 300 and a blood filter 303, the blood filter 303 comprising a semipermeable membrane 303c.

[0102] When using reference numbers for components of a blood treatment device, please refer to the reference numbers in Figures 1 and 2.

[0103] This method optionally includes, as M1, the step of detecting air bubbles or air pockets in the extracorporeal blood circuit 300, or the step of detecting an air bubble alarm. Air bubbles or air pockets may be detected using an air bubble detector 315. Alternatively or additionally, the latter may be preferably configured to trigger an air bubble or gas bubble alarm as a result of detecting an air bubble.

[0104] In certain embodiments, step M1 is not considered part of the method according to the present invention, but rather a prerequisite for carrying it out.

[0105] Method step M2 represents stopping the blood pump 101, or alternatively, reducing its transport rate relative to the transport rate provided immediately before the detection of air bubbles.

[0106] Optional method step M3 represents fully or partially closing the venous tube clamp 306.

[0107] While the blood pump 101 is stopped or its transport speed is reduced, the corresponding operation of the hydraulic pump on the blood treatment device, in this case the ultrafiltration pump 131, creates a negative intermembrane pressure difference P across the semipermeable membrane 303c. TM The generation of is represented by method step M4.

[0108] Step M5 of the method involves a negative intermembrane pressure difference P. TM Maintaining a negative intermembrane pressure difference P TM When it has already been generated, or when the intermembrane pressure difference P TM When the value is negative, it indicates that the venous tube clamp 306 is opened.

[0109] In some embodiments, the minimum negative intermembrane pressure difference P is then detected by, for example, at least one pressure sensor PS4 of the blood treatment device 100. TM_min When detected, the venous tube clamp 306 is opened.

[0110] In some embodiments, a pressure sensor PS3 (vein sensor) or a pressure sensor PS2 is used to evaluate the pressure conditions. In these and any other embodiments, the determined pressure may be monitored to detect a pressure drop and open the vein tube clamp 306 accordingly. From experience, the operating pressure during treatment is mostly about 320 mmHg for PS3 and about 300 mmHg for PS2.

[0111] Due to the negative transmembrane pressure difference, (membrane-permeating) plasma water movement occurs through the membrane, and the blood is concentrated in the dialyzer. As a result, the amount pumped into the hydraulic system is replaced by the blood flowing out of the patient through the venous tube system in the opposite direction to the normal flow direction. Air bubbles or air pockets (gas bubbles and microbubbles) located in the tube are returned to the venous air separation chamber, where they are separated, for example, into the environment.

[0112] In certain embodiments, while the optional replacement pump 111 of the blood treatment device 100 is stopped or not pumping, the negative transmembrane pressure difference P TM is generated by the pump.

[0113] The method step M6 represents, for example, stopping the generation or maintenance of the negative transmembrane pressure difference P TM when a predetermined negative transmembrane pressure difference P in the range of, for example, -300 mmHg to -500 mmHg is reached, or when at least 30 to 60 ml of blood is conveyed towards the arterial needle or the venous air separation chamber 329 due to or as a result of the generated transmembrane pressure difference P TM TM [[ID=,16]]

[0114] Alternatively, in method step M7, conveying through the pump to generate the negative transmembrane pressure difference P TM ends after the bubble detector 315 stops detecting bubbles or air pockets and / or after the bubble alarm stops.

[0115] The pump for conveying the dialysis liquid and / or dialysate on the hydraulic side of the blood treatment device 100 can be, for example, an ultrafiltration pump 131. The invention described in the claims of the original application is listed below. [Claim 1] A method for controlling a blood treatment apparatus comprising a blood pump, a bubble detector, and a pump for transporting dialysate and / or dialysate during an extracorporeal blood treatment session in which the blood treatment apparatus is connected to an extracorporeal blood circuit and a blood filter having a semipermeable membrane, The method described above is performed after detecting air bubbles in the extracorporeal blood circuit, or after an air bubble alarm is recognized or triggered by the air bubble detector. - Stopping the blood pump or reducing the transport speed that was provided immediately before the detection of the air bubble, - To generate a negative intermembrane pressure difference across the semipermeable membrane by appropriately operating the blood pump while the blood pump is stopped or while its transport speed is reduced, A method comprising the steps of performing a certain action. [2] The generation of the negative intermembrane pressure difference across the semipermeable membrane is performed with the venous tube clamp fully or partially closed, as described in [1]. [3] - The procedure further comprises the step of opening the venous tube clamp while maintaining the negative intermembrane pressure difference when a negative intermembrane pressure difference has already been generated. The method described in [2]. [4] The method according to [3], wherein the venous tube clamp is opened when it is determined via a pressure sensor of the hematology device that a negative minimum intermembrane pressure difference has been achieved. [5] The method according to any one of [1] to [4], wherein a negative intermembrane pressure difference is generated by the pump while the optionally selected replacement fluid pump of the blood treatment device is stopped or not transporting fluid. [6] - For example, when a predetermined negative intermembrane pressure difference of -300 mmHg to -500 mmHg is reached, or when at least 30 to 60 ml or more of blood is delivered toward the arterial connection needle or venous air separation chamber due to or resulting from the generated intermembrane pressure difference, the generation or maintenance of the negative intermembrane pressure difference is terminated. The method described in any one of the items [1] to [5]. [7] - The pumping to generate a negative intermembrane pressure difference is terminated after the bubble detector no longer detects bubbles or air pockets and / or after a bubble alarm or a predetermined criterion for this purpose has ceased to exist. The method described in any one of the items [1] to [6]. [8] The method according to any one of [1] to [7], wherein the pump for transporting the dialysate and / or dialysate is an ultrafiltration pump. [9] A control device or closed-loop control device configured to interact with a blood treatment device to initiate or perform the method described in any one of [1] to [8].

[10] In any case, at least, - Blood pump and, - Bubble detector and, - A pump for transporting dialysate and / or dialysate, - A control device or closed-loop control device, in particular the one described in [9], configured to initiate the execution of the method described in any one of the items [1] to [8], A blood treatment device equipped with, or connected to, these.

[11] The blood treatment device according to

[10] , which is connected to an extracorporeal blood circuit and a blood filter having a semipermeable membrane.

[12] The extracorporeal blood circuit is a blood tube set and / or a blood cassette, or comprises the blood treatment device according to

[11] .

[13] The blood treatment apparatus according to any one of

[10] to

[12] , wherein the pump for transporting the dialysate and / or dialysate is an ultrafiltration pump.

[14] A blood treatment device as described in any one of

[10] to

[13] , which is embodied as a hemodialysis machine, a hemofiltration machine, a hemodiafiltration machine, or a device for performing a separation method.

[15] A digital storage medium having an electronically readable control signal, particularly in the form of a floppy disk, CD or DVD or EPROM, configured to configure a control device or closed-loop control device to a control device or closed-loop control device according to the present invention, and / or a blood treatment device to a blood treatment device according to the present invention, through which the method described in any one of [1] to [8] can be initiated or executed.

[16] A computer program product having program code stored on a machine-readable carrier for configuring a control device or closed-loop control device to a control device or closed-loop control device according to the present invention, and / or for configuring a blood treatment device to a blood treatment device according to the present invention, wherein a method according to any one of [1] to [8] can be initiated or executed therefrom.

[17] A computer program having program code for configuring a control device or closed-loop control device to a control device or closed-loop control device according to the present invention, and for configuring a blood treatment device to a blood treatment device according to the present invention, wherein in either case, the method described in any one of [1] to [8] can be initiated and executed. [Explanation of Symbols]

[0116] 100... Blood treatment device 101... Blood pump 102... Dialysis fluid outlet line 104... Dialysis fluid inlet line 105... Replacement fluid line 107... Front dilution valve 107a...Line associated with the front dilution valve 109... Rear dilution valve 109a...Line associated with the rear dilution valve 111... Replacement fluid pump 131...Ultrafiltration pump 150... Control devices 153...Waste Exit 155…Water supply source 157...Heat exchanger 159...First flow pump 161... Balancing device 162…Heating devices 163... Mixing device 163a... Conductivity sensor 163b... Conductivity sensor 165a...Temperature sensor 165b...Temperature sensor 166...Concentrate supply section 167... Leak sensor 168...Concentrate supply section 169...Second flow pump 171... Pump, sodium pump 173... Pumps, bicarbonate pumps 175... Compressed air source, compressor 300...Extracorporeal blood circuit 301...First line (arterial side line portion) 302… (First) tube clamp, arterial tube clamp 303... Blood filter or dialyzer 303a... Dialysis fluid chamber 303b... Blood Chamber 303c…Semi-permeable membrane 305...Second line (venous line portion) 306… (Second) tube clamp, venous tube clamp 315...Bubble detector 317... Single needle chamber 318... Degassing device 319... Detector 325... Addition site for heparin 329...Venous air separation chamber F1...Filter F2…Filter A... Holder B... Holder K... Compressed air source, compressor PS1…Arterial pressure sensor (optional) PS2…Arterial pressure sensor (optional) PS3... Pressure sensor (optional) PS4... Pressure sensor for measuring filtrate pressure P TM ...negative intermembrane pressure difference P TM_min ...Negative minimum intermembrane pressure difference M1~M7...Method Steps V... valve VB...Bypass valve Y...Y-connector

Claims

1. A method for controlling a blood treatment apparatus comprising a blood pump, a bubble detector, and a pump for transporting dialysate and / or dialysate during an extracorporeal blood treatment session in which the blood treatment apparatus is connected to an extracorporeal blood circuit and a blood filter having a semipermeable membrane, The method described above is performed after detecting air bubbles in the extracorporeal blood circuit, or after an air bubble alarm is recognized or triggered by the air bubble detector. - Stopping the blood pump, or reducing the transport speed that was provided immediately before the detection of the air bubbles, - While the blood pump is stopped or its transport speed is reduced, by appropriately operating the pump, a negative intermembrane pressure difference is generated across the semipermeable membrane, and in this case, the air bubbles in the extracorporeal blood circuit are transported back to the venous air separation chamber by the negative intermembrane pressure difference. A method comprising the steps of performing a certain action.

2. The method according to claim 1, wherein the generation of the negative intermembrane pressure difference across the semipermeable membrane is performed with the venous tube clamp fully or partially closed.

3. - The procedure further comprises the step of opening the venous tube clamp while maintaining the negative intermembrane pressure difference when a negative intermembrane pressure difference has already been generated. The method according to claim 2.

4. The method according to claim 3, wherein the venous tube clamp is opened when it is determined via the pressure sensor of the blood treatment device that a negative minimum intermembrane pressure difference has been achieved.

5. The method according to claim 1, wherein a negative intermembrane pressure difference is generated by the pump while an optional blood pump of the blood treatment device is stopped or the transport speed of the blood pump is reduced.

6. --When a predetermined negative intermembrane pressure difference of -300 mmHg to -500 mmHg is reached, or when at least 30 ml of blood is transported toward the arterial connection needle or venous air separation chamber by the generated intermembrane pressure difference, the generation or maintenance of the negative intermembrane pressure difference is terminated. The method according to claim 1.

7. - The pumping to generate a negative intermembrane pressure difference is terminated after the bubble detector no longer detects bubbles or air pockets, and / or after a bubble alarm or a predetermined criterion for this purpose no longer exists. The method according to claim 1.

8. The method according to claim 1, wherein the pump for transporting the dialysate and / or dialysate is an ultrafiltration pump.

9. A control device or closed-loop control device configured to interact with a blood treatment device to initiate or carry out the method described in claim 1.

10. In either case, at least, - Blood pump and, - Bubble detector and, - A pump for transporting the dialysate and / or dialysate, - A control device or closed-loop control device according to claim 9, configured to initiate the execution of the method according to claim 1, A blood treatment device equipped with, or connected to, these.

11. The blood treatment device according to claim 10, which is connected to an extracorporeal blood circuit and a blood filter having a semipermeable membrane.

12. The blood treatment apparatus according to claim 11, wherein the extracorporeal blood circuit is a blood tube set and / or a blood cassette, or comprises the same.

13. The blood treatment apparatus according to any one of claims 10 to 12, wherein the pump for transporting the dialysate and / or dialysate is an ultrafiltration pump.

14. A blood treatment device according to any one of claims 10 to 12, which is embodied as a hemodialysis machine, a hemofiltration machine, a hemodiafiltration machine, or a device for carrying out a separation method.

15. A machine-readable digital recording medium that stores a program for causing a computer in a control device, a closed-loop control device, or a blood treatment device to perform the method according to any one of claims 1 to 8.

16. A computer program for causing a computer in a control device or a closed-loop control device or a blood treatment device to perform the method according to any one of claims 1 to 8.

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