Method and devices for testing at least one function of a medical functional device

0001The present invention relates to a method according to claim 1. It also relates to a detection device according to claim 8 and a medical treatment device according to claim 12.

0002Machine tests for checking the function and reliability of medical functional devices such as extracorporeal blood tubes, blood cassettes and the like are known from practice. Such a test is known as a pressure maintenance test. It is carried out after the functional device in question is connected to the treatment device, that is to say after the treatment device has already been upgraded with the functional device, and before the treatment of the patient begins.

0003In the patent application <patcit id="pcit0001" dnum="US20040223857A1"><text>US 2004/0223857 A1</text></patcit> describes a blood component processing system that includes a cassette and a controller. The controller checks the installation and integrity of the cassette.

0004The patent application <patcit id="pcit0002" dnum="DE102207042964A1"><text>DE 102207 042 964 A1</text></patcit> describes a method for checking the tightness of a medical cassette with liquid-carrying channels, which are covered by a flexible film. The possibility of continuously sucking air between the flexible film and a coupling surface gives the possibility of determining leaks in the film.

0005An object of the present invention is to propose a further method for checking the function of medical functional devices. In addition, suitable devices, a suitable digital storage medium, a suitable computer program product and a suitable computer program are to be specified.

0006The object of the invention is achieved by a method having the features of claim 1. It is also achieved by means of the detection device with the features of claim 8 and the treatment device with the features of claim 12.

0007According to the invention, a method is therefore proposed for checking at least one function of a medical functional device while it is inserted into and connected to a medical treatment device, in particular in fluid communication, and / or for checking a function of the treatment device connected to the functional device.

0008The method can include inserting the functional device into the medical treatment device or at least presupposes this.

0009The method can further include pressing, pretensioning or clamping the functional device in the treatment device, for example by means of the door of the treatment device. Alternatively, it requires this.

0010Furthermore, the method can include establishing at least one fluid communication between a hydraulic device or a pneumatic unit of the treatment device and the functional device. Alternatively, this state exists before the start of the process.

0011The method according to the invention comprises building up a pressure by means of the hydraulic device or a pneumatic unit within the fluid communication. It also includes a subsequent measurement of a pressure prevailing after the pressure has built up within the fluid communication or a pressure change such as a pressure increase or a pressure drop.

0012Furthermore, the method according to the invention includes making a statement about the checked function of the functional device on the basis of a comparison of the prevailing pressure or the measured pressure change with previously stored values, threshold values, ranges or courses.

0013The detection device according to the invention is suitable and provided and / or designed and / or configured to carry out the method according to the invention.

0014The medical or medical technology treatment device according to the invention (hereinafter also briefly: treatment device) has at least one detection device and / or is connected to it in signal transmission or is in a signal transmission relationship with it.

0015A digital, in particular non-volatile, storage medium according to the invention, in particular in the form of a machine-readable carrier, in particular in the form of a floppy disk, CD, DVD or EPROM, in particular with control signals which can be read out electronically or optically, can interact with a programmable computer system in such a way that the machine steps of an inventive step Procedure are initiated.

0016All, some or some of the mechanically performed steps of the method according to the invention can be initiated.

0017A computer program product according to the invention has a volatile, volatile or program code stored on a machine-readable carrier for initiating the machine steps of the method according to the invention when the computer program product runs on a computer. According to the invention, a computer program product can include, for example, a computer program stored on a carrier, an embedded system as a comprehensive system with a computer program (e.g. electronic device with a computer program), a network of computer-implemented computer programs (e.g. client / server system, cloud computing system, etc.), or a computer on which a computer program is loaded, runs, stored, executed or developed, be understood.

0018The term "machine-readable carrier" as used herein denotes, in certain embodiments of the present invention, a carrier that contains data or information that can be interpreted by software and / or hardware. The carrier can be a data carrier, such as a floppy disk, a CD, DVD, a USB stick, a flash card, an SD card and the like.

0019A computer program according to the invention has a program code for initiating the machine steps of the method according to the invention when the computer program runs on a computer. According to the invention, a computer program can be understood to mean, for example, a physical, marketable software product that has a program.

0020It also applies to the computer program product according to the invention and the computer program according to the invention that all, some or some of the mechanically performed steps of the method according to the invention are initiated.

0021In all of the following explanations, the use of the expression “may be” or “may have” etc. is synonymous with “is preferably” or “preferably” etc. and is intended to explain an embodiment of the invention.

0022Advantageous further developments of the present invention are the subject of subclaims and embodiments.

0023Embodiments according to the invention can have one or more of the features mentioned below.

0024In some embodiments according to the invention, a predetermined waiting time or measurement time is waited for before a statement is made about the function tested.

0025Measuring a pressure or a change in pressure can comprise any type of determination, for example measuring by means of a sensor, calculation, closing based on numerical values ​​of other parameters or circumstances, etc.

0026Likewise, as used herein, determining can be checking for or not, measuring, "coming to a result or statement", recognizing, determining, or the like.

0027In some embodiments of the invention, the devices, devices, apparatus, and other objects described herein have or are associated with the devices, devices, apparatus, or other objects required to perform method steps or test steps described herein.

0028In certain embodiments of the method according to the invention, the build-up of a pressure by means of the hydraulic device or the pneumatic unit within the fluid communication is only carried out if, when a pre-pressure which is lower than the pressure to be built up is applied beforehand, none - or, based on a specification, is too great - Functional deviation was found. The functional deviation is too great, for example, if a leak is detected when a form is created.

0029In some embodiments according to the invention, the method comprises filling, in particular complete filling, the dialysate side and / or the blood side of a blood filter, to which the functional device is connected in fluid communication.

0030In certain embodiments according to the invention, the method comprises building up the pressure by means of a substituate pump of the treatment device.

0031In some embodiments according to the invention, the method comprises building up the pressure against the standing or, if need be, defined, pumping substituate pump.

0032In some embodiments of the invention, the method includes determining or measuring a pressure drop or pressure increase within the fluid communication. It also includes that a continuity (or lack of continuity) of the fluid communication or the functional device is determined or postulated on the basis of a comparison of the determined pressure drop or pressure rise with previously stored values, threshold values, ranges or courses.

0033In certain embodiments according to the invention, the method comprises determining or measuring a pressure drop or pressure rise - in particular within a predetermined time period - within the fluid communication. It also includes the determination (determination is also used or to be understood synonymously here with a recognition, a postulation, etc.) of a tightness or a lack of tightness of the fluid communication or the functional device. This determination is based on a comparison of the detected pressure drop or pressure increase with previously stored values, threshold values, ranges or courses.

0034In certain embodiments according to the invention, the detection of a pressure drop or pressure rise within the fluid communication takes place within a predetermined period of time.

0035In embodiments of the invention, the method comprises the delivery of a predetermined delivery volume within the fluid communication when the automatic substituate connector is connected with or by means of a backward-running substituate pump against a check valve which is provided within a substituate channel. The method of these embodiments further includes determining a pressure change within the fluid communication. It also includes determining a check function (or non-function) of the check valve in the event that a detected pressure drop is not equal to or higher than a maximum pressure drop. Alternatively, an increase in pressure behind the check valve can of course also be monitored to check the check function. Under a backward running pump, e.g. B. Substitute pump is to be understood as a pump which conveys in a direction opposite to the direction (forwards) in which the considered pump conveys, at least predominantly, during the treatment of the patient.

0036In embodiments according to the invention, the method comprises the delivery of a predetermined delivery volume when the automatic substituate connector is connected within the fluid communication with the substituate pump running backwards against a check valve which is provided within a substituate channel. It also includes determining a change in pressure within the fluid communication, and determining that the substituate pump is delivering or has advanced if a determined pressure drop is greater than a maximum pressure drop.

0037In certain embodiments, the method according to the invention comprises determining a current pressure value at a later, second point in time, starting from an already existing pressure value at an earlier, first point in time, from a measured value and from a predetermined smoothing factor or multiplier - in particular during a pressure holding phase - according to the formula: <maths id="math0001" num=""><math display="block"><mrow><mi>VALUE_new</mi><mo>=</mo><mi>VALUE_old</mi><mo>*</mo><mi>GF</mi><mo>+</mo><mi>MEASURED VALUE</mi><mo>*</mo><mfenced separators=""><mn>1</mn><mo>−</mo><mi>GF</mi></mfenced></mrow></math><img file="EP2736558B1_D0001.tif" /></maths> where:<dl id="dl0001"><dt>VALUE_new</dt><dd>is a current pressure value, it can be a fictitious or calculated value;</dd><dt>VALUE_old</dt><dd>is the pressure value already available or determined at an earlier point in time, it can also be a fictitious or - in particular calculated using the formula discussed here;</dd><dt>GF</dt><dd>is a smoothing factor; and</dd><dt>MEASURED VALUE</dt><dd>is a pressure currently measured, i.e. at a later, second point in time.</dd></dl>

0038In certain embodiments of the method according to the invention, the smoothing factor is in a range from 0.9 to 0.96, in particular it corresponds to 0.93.

0039In some embodiments according to the invention, the method comprises filling an extracorporeal blood circuit connected to the functional device - preferably in such a way that it is free of air - before the pressure is built up.

0040In some embodiments of the method according to the invention, at least one function, in particular the opening, the closing or a sealing function, of at least the valve is used for an addition point for substituate in predilution; a valve for an addition site for substituent in post-dilution; a single-needle valve; a check valve in the substituate channel; and / or an automatic substituate connector checked.

0041In certain embodiments according to the invention, the method is carried out before starting treatment of a patient in which the functional device is used.

0042In embodiments of the invention, the method includes blocking treatment modalities and / or restricting treatment parameters of the treatment method or the treatment modality. The blocking or restricting takes place based on (or including) a result of the checking of at least one function of the medical functional device and / or the treatment device by the present method.

0043In embodiments of the method according to the invention, the medical functional device is a blood cassette and the treatment device is a blood treatment device.

0044In some embodiments according to the invention, the detection device has at least one display device for displaying a result of the implementation of the method according to the invention. The display device can be a display, an error display or the like.

0045In certain embodiments according to the invention, the detection device has at least one alarm device for outputting an alarm. The alarm device can be provided or configured to output an alarm in the event that the result of carrying out the method according to the invention is not in a predetermined range or range of values. The alarm can be an acoustic and / or a visual alarm.

0046In certain embodiments according to the invention, the detection device is programmed and / or configured to act on the treatment device in such a way that at least one treatment option or modality (e.g. a dialysis method, in particular as enumerated herein), for which the checked functional device can be used as intended or for design reasons (and) and / or the treatment under predetermined treatment parameters by means of the specific, checked functional device cannot be carried out. This applies in the event that a lack of functionality - e.g. B. inadequate closing, opening or sealing - the functional device and / or the treatment device (or a component thereof, in particular the valve of the addition point for substituate in predilution and / or a valve of the addition point for substituate in postdilution) was detected in this method.

0047In some embodiments, the treatment device acts on the treatment device in such a way that the treatment option (s) hemofiltration and / or hemodiafiltration cannot be carried out by means of the specific, tested functional device.

0048In some embodiments according to the invention, the detection device is a control or regulating device and / or a function test monitor or has one or more of these.

0049In certain embodiments according to the invention, the medical treatment device is designed as a blood treatment device, in particular as a device for apheresis or dialysis, again in particular for hemodialysis, hemofiltration, hemodiafiltration.

0050Some or all of the embodiments of the invention may have one or more of the advantages mentioned above or below.

0051Thus, since safety-relevant functions of the articles used and of the treatment device are checked according to the invention, increased safety for the patient can be created.

0052Since the method according to the invention can be carried out when preparing or upgrading the treatment device, a technical error can be recognized before the patient is connected and before blood has come into contact with the treatment device and the extracorporeal blood circuit. The latter avoids unnecessary additional consumption of disposable items. It also allows simple, early replacement of defective components in the event of a fault.

0053Since the method according to the invention can be carried out in embodiments according to the invention without any action on the part of the staff on duty, but instead runs automatically, it is advantageously possible to identify errors in a manner which saves working time and even before the start of treatment. In addition, the procedure described here, in that it can be carried out automatically, means that relevant test steps or procedures cannot be forgotten. The present invention is explained below by way of example with reference to the accompanying drawings, in which identical reference numerals designate identical or similar components. In the sometimes very simplified figures:<dl id="dl0002" compact="compact"><dt>Fig. 1</dt><dd>shows a schematically simplified diagram of a treatment device according to the invention with a blood cassette, which can be checked by means of the present invention; and</dd><dt>Fig. 2</dt><dd>shows schematically simplified a pneumatic circuit diagram of a treatment device according to the invention.</dd></dl>

0054<figref idref="f0001">Fig. 1</figref> shows a diagram of a treatment device according to the invention with a blood cassette and its components, which are explained for a better understanding of the exemplary embodiments of the present invention explained below.

0055An extracorporeal blood circuit 1 runs outside and inside a blood cassette 2 and connects it to a treatment device 4. The extracorporeal blood circuit 1 has or is connected to an access device (not shown), for example an arterial connection needle. A fluid flow through the extracorporeal blood circuit 1 or sections thereof can be prevented by means of an arterial patient hose clamp 6, arranged in its arterial patient hose 8 (also referred to as arterial blood line), and also by means of a venous patient hose clamp 7 in its venous patient hose 9 (also as a venous blood line) designated).

0056A section of the extracorporeal blood circuit 1 is inserted into a blood pump 11. The extracorporeal blood circuit 1 has an addition point 13 for substituate fluid (in predilution) and an addition point 14 for substituate fluid (in postdilution). The addition points 13 and 14 are exemplified here as phantom valves. Phantom valves of this type are in the<patcit id="pcit0003" dnum="WO2010121819A"><text>WO 2010/121819</text></patcit> the applicant also described the present invention. For details, reference is made to that published specification.

0057An arterial air-blood detector 15 is provided on the arterial blood line 8.

0058<figref idref="f0001">Fig. 1</figref> also shows a substituate pump 17. This is located downstream of a connection point at which the blood cassette 2 can be connected with its substituate port 18a to an automatic substituate connector 18b of the treatment device 4 before it is used. In the example, the automatic substituate connector 18b has the<figref idref="f0001">Fig. 1</figref> a first fluid guide 3, a second fluid guide 5 and a third fluid guide 10 for rinsing the automatic substituate connector 18b and for guiding substituate through the automatic substituate connector 18b.

0059A blood filter 19 with a blood chamber 19a and a dialysate chamber 19b is switched on in the extracorporeal blood circuit 1.

0060The blood cassette 2 has a venous air separation chamber 21.

0061A substituate line of the blood cassette 2 has a check valve 23.

0062The extracorporeal blood circuit 1 has a venous air substituate liquid blood detector 25 on the venous blood line 9.

0063The treatment device 4 has a compressed air source 26 or is connected to it. It also has a control or regulating device 28 or is connected to it.

0064In <figref idref="f0001">Fig. 1</figref> A dialysis liquid supply line 31a, which leads dialysis liquid to the dialysate chamber 19b, and a dialysate discharge line 31b, which leads dialysate away from the dialysate chamber 19b, can also be seen.

0065A pressure sensor 33a is provided upstream of the blood pump 11 in the arterial blood line 8.

0066A pressure sensor 33b is provided in the area of ​​the venous air separation chamber 21 in the venous blood line 9.

0067A pressure sensor 33c, also referred to as a prefilter pressure sensor, is provided downstream of the blood pump 11 in the arterial blood line 8. This can be arranged upstream of the addition point 13.

0068The blood cassette 2 has a single-needle valve 35.

0069Yet another pressure sensor 37 is located in or on the dialysis fluid supply line 31a between the pressure source 26 and the blood filter 19.

0070Valves V19, V24, V25, V28, V31, V32 and V33 are provided in sections of the hydraulic system of the treatment device 4.

0071The valve V24 is located in or on the dialysis fluid supply line 31a.

0072The valve V25 is in or on the dialysate drain line 31b.

0073The valve V28 lies in a drain line 45.

0074The valve V31 lies in the first fluid guide 3 of the automatic substituate connector 18b or in a line leading to it.

0075The valve V32 lies in the second fluid guide 5 of the automatic substituate connector 18b or in a line leading to it.

0076The valve V33 is in turn in the drain line 45.

0077The valve V19 is downstream of all of the aforementioned valves V24, V25, V28, V31, V32 and V33.

0078A hydraulic balancing chamber 40 is only indicated.

0079<figref idref="f0002">Fig. 2</figref> shows a pneumatic circuit diagram of a treatment device according to the invention. The components shown herein again serve to better understand the exemplary embodiments of the present invention explained below.

0080In <figref idref="f0002">Fig. 2</figref> an air distribution plate 100 is shown, which is connected to a pneumatic unit 200. A single-needle unit 300 is also shown.

0081The air distribution plate 100 has connections to the addition point 13, to the addition point 14, to the single-needle valve 35, to a braking device 11 'of the blood pump 11, to a braking device 17' of the substituate pump 17, and to further components, which are not discussed further here.

0082The pneumatic unit 200 is used as a compressed air source 26 (see <figref idref="f0001">Fig. 1</figref>) connected to the hydraulics of the treatment device 4.

0083The single-needle unit 300 has a ventilation 301, a single-needle compressor 350, a bypass valve 352, a ventilation valve 354, a pressure sensor 356 on the single-needle pressure vessel, a pressure sensor 358 of the SN line , an absolute pressure sensor 360, and a temperature sensor 362 in the SN pressure vessel. A connector 370 connects the single-needle unit 300 to the single-needle chamber of the blood cassette 2.

0084For the meaning of the other elements identified in the figures, reference is made to the list of reference symbols below.

0085The following first exemplary embodiment relates to a leak test in a disposable, here a blood cassette 2, which has no single-needle (SN) chamber or in which a single-needle chamber is separated from the extracorporeal blood circuit 1 by a single-needle valve 35 and stays. Here, it is checked whether the blood cassette 2 is tight to the outside or sufficiently tight. Furthermore, when the door is closed and pressed with the blood cassette 2 inserted, it is checked whether a pressure in the extracorporeal blood circuit 1 (also briefly: EB 1, 1 indicating the reference symbol) can be built up and maintained. This test can in particular be used to check whether the tightness of the extracorporeal blood circuit 1 (without patient tubing) is present, the stoppage leakage of both blood pump rollers, and / or whether there is sufficient compression to seal the flow paths and their branches in the blood cassette 2.

0086In addition, the function of the check valve 23 in the substituate channel can be checked by means of the procedure described below, in particular the functions "closing" and "sealing" of the check valve 23 in the blood cassette 2.

0087To carry out the test, the blood cassette 2 is inserted into the treatment device and pressed against the treatment device by closing a door. The dialyzer or blood filter 19 is connected and filled on the disposable and hydraulic side. The extracorporeal blood circuit 1 is filled with liquid and largely free of air. The EB 1 is alarm-free, the blood system is active, the hydraulics are in a preparation stage, the dialysate flow is switched on. The arterial patient tube 8 and the venous patient tube 9 are both connected to the irrigation port, not shown, via a T-piece.

0088At the start of the test of this embodiment according to the invention, the automatic substituate connector 18b is in the connection position. The substituate supply line or branch is or are filled.

0089The valve V33 is closed. The hydraulics are put into the so-called extended bypass (the valves V24, V25 are de-energized). The valve V31 is open. The arterial patient hose clamp 6 and the venous patient hose clamp 7 are open (energized). The pre-dilution valve 13 and the post-dilution valve 14 are open, the single-needle valve 35 is closed.

0090If the pressure in the hydraulic system exceeds the predetermined pressure PTESTSTART_HYD (measured by means of pressure sensor 37, arranged on the dialysis fluid supply line 31a), this is reduced using the substituate pump 17. To do this, V33 is opened and the substituate is pumped until the hydraulic pressure (again measured using pressure sensor 37) has dropped below the pressure PTESTSTART_HYD. Subsequently, the substituate pump 17 is stopped and V33 is closed again.

0091If the pressure in the hydraulic system does not exceed the predetermined pressure PTESTSTART_HYD, it is checked whether the pressure in the EB 1 exceeds the predetermined pressure PTESTSTART_EB (measured on the pressure sensor 33b in the area of ​​the venous air separation chamber 21). If this is the case, it is dismantled by opening valve V33 of the hydraulics; valve V33 is then closed.

0092The blood pump rotor of the blood pump 11 is then positioned such that only a first role of the pump rotor is in engagement with the extracorporeal blood circuit 1. Then both the arterial patient hose clamp 6 and the venous patient hose clamp 7 are closed and a predetermined waiting time PRESSURE COMPENSATION TIME is waited for pressure compensation, and the arterial starting pressure (measured by means of pressure sensor 33a of the arterial blood line) is noted in order to determine the roll stop leakage.

0093With the substituate pump 17, liquid is conveyed into the EB 1 by means of a predetermined flow SUBSTITUATE PUMP: FLOW. First, the prefilter pressure sensor 33c is used to check whether a test pressure PRUEFDRUCK in EB 1 can be built up within a defined time interval TIMEOUT.

0094If this is the case, the substituate pump 17 is stopped after this intermediate test has been passed. After that, a reasonable time PRESSURE COMPENSATION is waited for a static pressure to develop. If the pressure has dropped below the minimum test pressure MIN TEST PRINT during the pressure equalization phase, the test is terminated with an error.

0095Otherwise, the following test step is carried out for the second role of the pump protector which differs from the first role. The pressure drop is determined within a defined period of time TESTTIME. The absolute pressure change is considered, whereby this must not exceed a maximum value MAXIMUM PRESSURE DROP.

0096In contrast, when the first roll is checked, a time period TESTTIME is waited without the pressure drop being assessed.

0097After passing the test, the arterial pressure increase is assessed. If this exceeds the specified pressure drop MAXIMUM STILL LEAKAGE, there is no complete occlusion.

0098The following test step is only carried out for the first role of the pump protector. It is tested whether the check valve 23 closes and seals in the substituate channel.

0099The test pressure previously built up is retained. The substituate pump 17 delivers backwards with the aim of delivering a maximum delivery volume MAX FOERDERVOLUMEN, and at the same time the absolute pressure drop measured at the pressure sensor 33c is evaluated. This may not exceed a MAXIMUM PRINT CHANGE value or its amount. At the same time, the pressure in the blood cassette 2 must not rise (if this is the case, the substituate pump 17 turns upside down).

0100Since the compartment between the check valve 23 and the adjacent substituate pump 17 is very small (&lt;3 ml), the volume that can be delivered by the substituate pump 17 is generally limited. If the check valve 23 does not close, the volume delivered depends on the maximum permissible pressure change MAXIMUM PRESSURE CHANGE. For a certain type of extracorporeal blood circuit 1 (in an air-free system) it applies that a pressure drop of 50 mbar corresponds approximately to a leakage of 250 μl.

0101In order to reduce the pressure in the EB 1, the arterial patient hose clamp 6, the venous patient hose clamp 7 and the valve V33 are energized.

0102The entire test is repeated for the other role of the blood pump rotor. To do this, the pressure drop in EB 1 is first waited for (PRESSURE COMPENSATION TIME), then the flushing port is closed and the step for positioning the blood pump rotor is continued.

0103In the event of a fault, the substituate pump 17 is stopped and the pressure in the EB 1 is reduced by opening the venous patient hose clamp 7 and energizing the hydraulic valves V33, V28 and V19.

0104Tests by the applicant have shown that a leak in the range of 5.5 ml / min to the outside or into the SN chamber can be detected by means of this test. Furthermore, it may be possible to identify non-compression and semi-compression of the blood cassette 2.

0105If the test fails, a single repetition is provided in some embodiments according to the invention. For safety reasons it can be provided that treatment of the patient is only possible when the test has been passed.

0106If the test is not passed, it may be necessary to disassemble the tested blood cassette 2 and to replace it with a new blood cassette 2. The new blood cassette 2 is refilled and rinsed.

0107Examples of preset values ​​for the above parameters are given in the following parameter table (Table 1):<tables id="tabl0001" num="0001"><table frame="all"><title>Table 1</title><tgroup cols="4"><colspec colnum="1" colname="col1" colwidth="47mm" /><colspec colnum="2" colname="col2" colwidth="58mm" /><colspec colnum="3" colname="col3" colwidth="16mm" /><colspec colnum="4" colname="col4" colwidth="15mm" /><thead><row><entry valign="top"><b>Subtest</b></entry><entry valign="top"><b>parameter</b></entry><entry valign="top"><b>unit</b></entry><entry valign="top"><b>value</b></entry></row></thead><tbody><row><entry morerows="3">general parameters</entry><entry>PRESSURE COMPENSATION</entry><entry>ms</entry><entry>2000</entry></row><row><entry>SUBSTITUTE PUMP: RIVER</entry><entry>ml min^-1</entry><entry>500</entry></row><row><entry>PTESTSTART_EB</entry><entry>mbar</entry><entry>67</entry></row><row><entry>PTESTSTART_HYD</entry><entry>mbar</entry><entry>333</entry></row><row><entry morerows="2">"Build up pressure"</entry><entry>TEST PRINT</entry><entry>mbar</entry><entry>1400</entry></row><row><entry>MIN PRESSURE PRESSURE</entry><entry>mbar</entry><entry>1250</entry></row><row><entry>TIME-OUT</entry><entry>ms</entry><entry>15000</entry></row><row><entry morerows="2">"Leak test"</entry><entry>TESTTIME</entry><entry>ms</entry><entry>5000</entry></row><row><entry>MAXIMUM PRESSURE DROP</entry><entry>mbar</entry><entry>73</entry></row><row><entry>MAXIMUM STILL LEAKAGE</entry><entry>mbar</entry><entry>400</entry></row><row><entry morerows="1">"Check valve check 23"</entry><entry>MAX FULL VOLUME</entry><entry>ml</entry><entry>5</entry></row><row><entry>MAXIMUM PRINT CHANGE</entry><entry>mbar</entry><entry>20</entry></row></tbody></tgroup></table></tables>

0108Errors that occur in the present test and suggestions for their correction are shown in the following error table (Table 2):<tables id="tabl0002" num="0002"><table frame="all"><title>Table 2</title><tgroup cols="2"><colspec colnum="1" colname="col1" colwidth="50mm" /><colspec colnum="2" colname="col2" colwidth="77mm" /><thead><row><entry valign="top"><b>Subtest</b></entry><entry valign="top"><b>error</b></entry></row></thead><tbody><row rowsep="0"><entry morerows="2" rowsep="1">"Build up pressure"</entry><entry>TIMEOUT exceeded</entry></row><row rowsep="0"><entry>→ SN valve 35 open</entry></row><row><entry>→ Disposable not completely pressed</entry></row><row rowsep="0"><entry morerows="3" rowsep="1">"Leak test"</entry><entry>MAX PRESSURE DROP exceeded</entry></row><row><entry>→ Disposable leaks</entry></row><row rowsep="0"><entry>MAXIMUM DOWNSTILL LEAK exceeded</entry></row><row><entry>→ Role incomplete in the intervention</entry></row><row rowsep="0"><entry morerows="2" rowsep="1">"Check valve check 23"</entry><entry>MAX PRINT CHANGE exceeded</entry></row><row rowsep="0"><entry>→ Check valve 23 is not tight or</entry></row><row><entry>→ Substitute pump 17 turns forward</entry></row></tbody></tgroup></table></tables>

0109With the test of this embodiment, e.g. B. leaky blood cassette 2 can be detected due to insufficient compression.

0110A leakage sensor can also be provided to detect further or other leaks.

0111The <b>second</b> The embodiment according to the invention relates to a test for checking the tightness of the substituate connection. This test checks whether the substituate connection (automatic substituate connector 18b (ASK) with substituate port 18a) is tight to the outside. In addition, the closure of the disposable is checked for continuity.

0112For this purpose, the blood cassette 2 is inserted into the treatment device and pressed. The roles of the substituate rotor are extended. The hydraulics are available. The automatic substituate connector 18b connects. A pressure maintenance test is carried out by means of the hydraulic system after the blood cassette 2 has been connected.

0113This test makes it possible to detect a leak in the area of ​​the automatic substituate connector 18b to the outside in the range of 1 ml / min (corresponds to approximately 500 ml / treatment). It is also possible to determine whether an online connection in the blood cassette 2 has been closed.

0114In some embodiments according to the invention, treatment of the patient is not possible without passing the test. This can be repeated any number of times. Alternatively, the blood cassette 2 is disassembled and exchanged for another blood cassette.

0115With the pressure-controlled filling program of the balancing chamber, pressure is built up in the area of ​​the pressure sensor 37 against the standing substituate pump 17 when the substituate connector is connected and the valve V31 is open. This pressure may only drop within certain limits during a holding phase. In order to keep the fluid leakage low in the event of a grossly leaky connection, a pre-test with low pressure is preceded in certain embodiments according to the invention.

0116In addition, the continuity between the hydraulics of the treatment device 4 and the substituate pump 17 is tested in that a pressure drop at the pressure sensor 37 is expected by moving or operating the substituate pump 17.

0117At or before the test begins, valve V31 and valve V24 are closed.

0118The addition point 13 is closed, as is the addition point 14. The substituate pump 17 stands.

0119A pressure-controlled filling program is started to start the test. A pressure value of LOW PRESSURE LIMITS is requested. There is a timeout period of e.g. B. waited 2 s, in which a minimum pressure LOW PRESSURE LIMITS should have built up or maintained within the scope of a rapid test. If this is not the case, not even within the waiting time TIMEOUT, then there is a problem with the hydraulics.

0120The pressure measured by means of pressure sensor 37 can be stored.

0121Then the valve V31 is repeatedly, e.g. B. three times (NV31), closed for a short time and reopened after a waiting time TV31. In the meantime, a predetermined minimum pressure MINIMUM PRESSURE must be maintained. V31 then remains open to see if a predetermined pressure drop is maintained. If the predetermined maximum pressure drop MAXDRUCKABFALL is exceeded, or if a predetermined minimum pressure MINDRUCK is not maintained, an error must be assumed; the test is then failed, possibly because the connection to the substituate port 18a is leaking. In this test section, the minimum hydraulic pressure can be monitored in order to rule out pressure build-up using the filling program.

0122After this quick test, a pressure-controlled filling program with a pressure HIGH PRESSURE LIMITS is started for a permeability test to build up pressure. If a predetermined pressure PRUEFDRUCK_HIGH is measured at the pressure sensor 37, the system switches on. If the minimum pressure at sensor 37 is not built up within a waiting time PRUEFDRUCK-TIMEOUT, although the hydraulics are available, then an error can again be assumed, for example from a roughly leaky substituate port 18a.

0123If, on the other hand, the expected minimum pressure is built up, a pressure-controlled filling program with low pressure limits LOW PRESSURE LIMITS is requested. After waiting for a PRESSURE COMPENSATION time, it must be checked whether the pressure measured by pressure sensor 37 falls below the expected minimum pressure MINPRUEFDRUCK. If this is the case, then an error can be assumed, which may result from a leaky connection to the substituate port 18a.

0124After a dead time PRINT COMPENSATION, the process continues.

0125The pressure measured by means of pressure sensor 37 can be stored.

0126In a next step, the valve for the addition point 14 is opened in order to wet the substituate pump and to test the blood cassette 2 for its permeability. The valve for the addition point 13 remains closed. The substituate pump 17 is moved forward by a predetermined volume SPVOLUMEN. A low flow SUBSTITUATE PUMP: FLOW can be set for this.

0127If the pressure drop then determined by means of pressure sensor 37 remains below an expected pressure drop or below a minimum pressure drop MINIMUM PRESSURE DROP, an error is concluded; the connection to the substituate port 18a may not be continuous.

0128Otherwise, the process proceeds to a leak test. For this purpose, the valve of the addition point 14 is closed.

0129A pressure-controlled filling program with a pressure HIGH PRESSURE LIMITS can be switched, which in turn serves to check the connection to the substituate port 18a. After the waiting time TIMEOUT has expired, during which a predetermined pressure PRUEFDRUCK_HIGH must be built up, otherwise a leaky connection to the substituate port 18a is assumed, the system switches to a pressure build-up as described above by means of a pressure-controlled filling program with low pressure limits. If certain criteria, such as pressure drop per second below a predetermined limit value MAXLECKAGE, are met after a MEASURING INTERVAL holding time, the test is passed. Otherwise, or if a waiting time MAX HOLD is exceeded, an error is assumed; the connection to the substituate port 18a may be leaky.

0130The following can be used to determine the pressure value during the pressure maintenance phase:<ul id="ul0001" list-style="none" compact="compact"><li>The pressure value is smoothed. Low-pass filtering with the smoothing factor GF = 0.93 is used:<maths id="math0002" num=""><math display="block"><mrow><mi>VALUE_new</mi><mo>=</mo><mi>VALUE_old</mi><mo>*</mo><mi>GF</mi><mo>+</mo><mi>MEASURED VALUE</mi><mo>*</mo><mfenced separators=""><mn>1</mn><mo>−</mo><mi>GF</mi></mfenced></mrow></math><img file="EP2736558B1_D0002.tif" /></maths></li></ul>

0131This pressure value is updated in every slice; the test for falling below the maximum leakage rate takes place every 2 seconds.

0132Examples of preset values ​​for the above parameters are given in the following parameter table (Table 3):<tables id="tabl0003" num="0003"><table frame="all"><title>Table 3</title><tgroup cols="4"><colspec colnum="1" colname="col1" colwidth="40mm" /><colspec colnum="2" colname="col2" colwidth="48mm" /><colspec colnum="3" colname="col3" colwidth="18mm" /><colspec colnum="4" colname="col4" colwidth="13mm" /><thead><row><entry valign="top"><b>Subtest</b></entry><entry valign="top"><b>parameter</b></entry><entry valign="top"><b>unit</b></entry><entry valign="top"><b>value</b></entry></row></thead><tbody><row><entry morerows="3">general parameters</entry><entry>PTESTSTART_HYD</entry><entry>mbar</entry><entry>200</entry></row><row><entry>PRESSURE COMPENSATION</entry><entry>ms</entry><entry>2000</entry></row><row><entry>LOW PRESSURE LIMIT</entry><entry>mbar</entry><entry>250</entry></row><row><entry>PRUEFDRUCK_HIGH</entry><entry>mbar</entry><entry>1100</entry></row><row><entry morerows="5">"Quick test"</entry><entry>SWITCHING TIME</entry><entry>ms</entry><entry>300</entry></row><row><entry>QUICK TEST</entry><entry>ms</entry><entry>1750</entry></row><row><entry>MAX PRESSURE DROP</entry><entry>%</entry><entry>75</entry></row><row><entry>MINIMUM PRINT</entry><entry>mbar</entry><entry>67</entry></row><row><entry>TV31</entry><entry>ms</entry><entry>250</entry></row><row><entry>NV31</entry><entry>number</entry><entry>3</entry></row><row><entry morerows="4">"Permeability test"</entry><entry>MINIMUM PRESSURE</entry><entry>mbar</entry><entry>1050</entry></row><row><entry>TIME-OUT</entry><entry>ms</entry><entry>2000</entry></row><row><entry>SUBSTITUTE PUMP: RIVER</entry><entry>ml min^-1</entry><entry>250</entry></row><row><entry>SPVOLUMEN</entry><entry>ml</entry><entry>12</entry></row><row><entry>MINIMUM PRESSURE DROP</entry><entry>mbar</entry><entry>133</entry></row><row><entry morerows="3">"Leak test"</entry><entry>TEST PRINT TIMEOUT</entry><entry>ms</entry><entry>2000</entry></row><row><entry>MAX LEAKAGE RATE</entry><entry>mbar / s^-1</entry><entry>2,67</entry></row><row><entry>MEASUREMENT INTERVAL</entry><entry>s</entry><entry>2</entry></row><row><entry>MAX HOLD TIME</entry><entry>s</entry><entry>25</entry></row></tbody></tgroup></table></tables>

0133Errors that occur in the present test and suggestions for their correction are shown in the following error table (Table 4):<tables id="tabl0004" num="0004"><table frame="all"><title>Table 4</title><tgroup cols="2"><colspec colnum="1" colname="col1" colwidth="40mm" /><colspec colnum="2" colname="col2" colwidth="106mm" /><thead><row><entry valign="top"><b>Subtest</b></entry><entry valign="top"><b>error</b></entry></row></thead><tbody><row rowsep="0"><entry morerows="4" rowsep="1">"Quick test"</entry><entry>TIMEOUT exceeded</entry></row><row rowsep="0"><entry>→ Test pressure could not be built up</entry></row><row><entry>→ Hydraulic problem</entry></row><row rowsep="0"><entry>MAX PRESSURE DROP exceeded or MINIMUM PRESSURE dropped below</entry></row><row><entry>→ Pressure drop too large: connection to the ASK roughly leaky</entry></row><row rowsep="0"><entry morerows="6" rowsep="1">"Permeability test"</entry><entry>TIMEOUT exceeded</entry></row><row rowsep="0"><entry>→ Connection to the ASK roughly leaky</entry></row><row><entry>→ or hydraulic problem</entry></row><row rowsep="0"><entry>MINIMUM PRESSURE dropped below</entry></row><row><entry>→ Connection to the ASK roughly leaky</entry></row><row rowsep="0"><entry>MINIMUM PRESSURE DROP not reached</entry></row><row><entry>→ Connection to the ASK not continuous</entry></row><row rowsep="0"><entry morerows="4" rowsep="1">"Leak test"</entry><entry>TIMEOUT exceeded</entry></row><row rowsep="0"><entry>→ Connection to the ASK roughly leaky</entry></row><row><entry>→ or hydraulic problem</entry></row><row rowsep="0"><entry>the MAX LEAKAGE was not exceeded during the HOLD time</entry></row><row><entry>→ ASK-Disposable connection leaking</entry></row></tbody></tgroup></table></tables>

0134The <b>third</b> Embodiment relates to a tightness and function test of the addition points 13 and 14 designed as phantom valves for substituate in predilution or in postdilution. It is checked whether the phantom valves open, close and seal, or whether pressure gradients can be built up and maintained when opening or closing the phantom valves. Possibly. "Hanging" or incorrectly closing phantom valves can be recognized here. This test can be repeated any number of times. If it is not passed sustainably, it can be disassembled and a new disposable inserted. Alternatively, a service employee can be informed. In certain embodiments according to the invention, treatment of the patient is not possible without passing the test. This test can also be carried out if the valves or addition points are not designed as phantom valves, but are of a different valve type.

0135To carry out this test, the blood cassette 2 is inserted and compressed as described above. The blood filter 19 is connected and filled on the disposable and hydraulic side. The extracorporeal blood circuit 1 is filled and largely free of air. The extracorporeal blood circuit 1 has preferably already passed the leak test of the first embodiment.

0136The arterial patient tube 8 and the venous patient tube 9 are each connected to the irrigation port via a T-piece.

0137At the start of the test, the hydraulics are put into the extended bypass. Valves V31 and V33 are energized at the same time and the pressure-controlled filling program is started. The valve V32 is closed.

0138The valve of the addition point 13 (predilution) is opened, that of the addition point 14 (postdilution) and the single-needle valve 35 remain closed. The arterial patient hose clamp 6 and the venous patient hose clamp 7 are or remain closed.

0139If the pressure in the hydraulic system exceeds a predetermined pressure PTESTSTART_HYD (measured by means of pressure sensor 37), this is reduced using the substituate pump 17 and a flow SUBSTITUATE PUMP: FLOW. The arterial patient hose clamp 6 and the venous patient hose clamp 7 can be opened for this. In any case, valve V33 is opened and substituate is pumped until the hydraulic pressure (measured by pressure sensor 37) has dropped below the pressure PTESTSTART_HYD. Subsequently, the substituate pump 17 is stopped and the valve V33 is closed again.

0140If the pressure in the hydraulic system does not exceed the predetermined pressure PTESTSTART_HYD (measured using pressure sensor 37), then pressure sensor 33b is used to check whether the pressure measured in extracorporeal blood circuit 1 exceeds pressure PTESTSTART_EB (measured on venous pressure sensor 33b). If this is the case, it is dismantled by opening valve V33 of the hydraulics; valve V33 is then closed.

0141For testing, the target pressure TEST PRESSURE in the extracorporeal blood circuit 1 is now built up with the substituate pump 17 (SUBSTITUATE PUMP: FLOW), measured by means of the pressure sensor 33b. This should be reached within the PRINTING TIMEOUT waiting time. If no such pressure build-up is found on the pressure sensor 33b, it is assumed that the valve of the addition point 13 does not open or that the single-needle valve 35 is open.

0142In the event of no fault, the addition point 13 is closed, the substituate pump 17 continuing to run. Normally, the pressure in the extracorporeal blood circuit 1 does not change after waiting for a PRESSURE COMPENSATION time during the subsequent MEASURING DURATION. If it nevertheless rises by a value greater than the pressure increase MAXIMUM PRESSURE RISE (measured by pressure sensor 33b), a problem with the valve (s) at the addition point (s) 13 and / or 14 can be concluded.

0143If the intermediate test has been passed, the substituate pump 17 is stopped and the pressure in the extracorporeal blood circuit 1 is reduced by opening the venous patient clamp 7 and the addition point 13 and waiting for the PRESSURE COMPENSATION TIME.

0144The check of addition point 14 (post dilution) is carried out analogously to that of addition point 13 (predilution).

0145By opening the venous patient hose clamp 7 and stopping the substituate pump 17, the pressure in the extracorporeal blood circuit 1 is reduced for the last time.

0146In the event of a fault, the pressure in the extracorporeal blood circuit 1 is reduced by opening the venous patient hose clamp 7 and stopping the substituate pump 17. Hemofiltration (HF) and hemodiafiltration (HDF) are then no longer possible.

0147Examples of preset values ​​for the above parameters are given in the following parameter table (Table 5):<tables id="tabl0005" num="0005"><table frame="all"><title>Table 5</title><tgroup cols="4"><colspec colnum="1" colname="col1" colwidth="46mm" /><colspec colnum="2" colname="col2" colwidth="51mm" /><colspec colnum="3" colname="col3" colwidth="16mm" /><colspec colnum="4" colname="col4" colwidth="15mm" /><thead><row><entry valign="top"><b>Subtest</b></entry><entry valign="top"><b>parameter</b></entry><entry valign="top"><b>unit</b></entry><entry valign="top"><b>value</b></entry></row></thead><tbody><row><entry morerows="3">General parameters</entry><entry>PRESSURE COMPENSATION</entry><entry>ms</entry><entry>2000</entry></row><row><entry>SUBSTITUTE PUMP: RIVER</entry><entry>ml min^-1</entry><entry>100</entry></row><row><entry>PTESTSTART_EB</entry><entry>mbar</entry><entry>67</entry></row><row><entry>PTESTSTART_HYD</entry><entry>mbar</entry><entry>333</entry></row><row><entry morerows="1">"Does valve 13 open?"</entry><entry>TEST PRINT</entry><entry>mbar</entry><entry>300</entry></row><row><entry>PRESSURE BUILDING TIMEOUT</entry><entry>ms</entry><entry>10000</entry></row><row><entry rowsep="0">"Does valve 13 close?</entry><entry>MAXIMUM PRESSURE RISE</entry><entry>mbar</entry><entry>4</entry></row><row><entry>Are valve 13 and valve 14 tight? "</entry><entry>MEASURING DURATION</entry><entry>ms</entry><entry>5000</entry></row><row><entry morerows="1">"Does valve 14 open?"</entry><entry>PRESSURE BUILDING TIMEOUT</entry><entry>ms</entry><entry>5000</entry></row><row><entry>TEST PRINT</entry><entry>mbar</entry><entry>300</entry></row></tbody></tgroup></table></tables>

0148Errors that occur in the present test and suggestions for their correction are shown in the following error table (Table 6):<tables id="tabl0006" num="0006"><table frame="all"><title>Table 6</title><tgroup cols="2"><colspec colnum="1" colname="col1" colwidth="76mm" /><colspec colnum="2" colname="col2" colwidth="79mm" /><thead><row><entry valign="top"><b>Subtest</b></entry><entry valign="top"><b>error</b></entry></row></thead><tbody><row rowsep="0"><entry morerows="1" rowsep="1">"Does valve 13 open?"</entry><entry>PRESSURE CREATION TIMEOUT exceeded</entry></row><row><entry>→ Valve 13 is not open</entry></row><row rowsep="0"><entry morerows="3" rowsep="1">"Does valve 13 close? Does valve 13 &amp; valve 14 close?"</entry><entry>Pressure increased by MAXIMUM PRESSURE RISE</entry></row><row rowsep="0"><entry>→ Valve 13 open</entry></row><row rowsep="0"><entry>→ Valve 14 open</entry></row><row><entry>→ Valve 13 and / or valve 14 is leaking</entry></row><row rowsep="0"><entry morerows="1" rowsep="1">"Does valve 14 open?"</entry><entry>TEST PRINT not reached</entry></row><row><entry>→ Valve 14 is not open</entry></row></tbody></tgroup></table></tables>

0149The <b>fourth</b> Embodiment relates to a leak test for the single-needle (SN) system. A test air is used to check whether the SN area is tight to the outside.

0150For this test, the blood cassette 2 is inserted and pressed as described above. The single-needle valve 35 is closed. A check is carried out to determine whether pressure can be built up and maintained in the single-needle positive and negative pressure compartments when the blood cassette 2 is pressed. Leaks in the SN system of 500 ml / 4 h and more can be detected.

0151If the test is not passed, it can be repeated as often as required. Alternatively, SN operation can be prevented or prevented. As always, the test can be repeated with a new disposable or the service can be informed.

0152In certain embodiments according to the invention, it is possible to combine this test with the functional test “SN pneumatic system” of the sixth embodiment.

0153The maximum amount of liquid or volume in the single-needle chamber is 10 ml.

0154At the beginning of the test, the bypass valve 352 is de-energized (= opened) and the vent valve 354 is energized (= opened). The single-needle valve 35 is closed. The single-needle system, including the SN tank, is brought to ambient pressure. This is the case when the SN pressure sensors 358 and 356 deviate from zero by a maximum of an OFFSET_MAX value. This process must be completed after a timeout TIMEOUT_INIT. Otherwise the starting conditions could not be established, for example because the vent valve 354 and / or the bypass valve 352 do not open correctly.

0155For the leak test, the vent valve 354 and the bypass valve 352 are closed to build up a test pressure. Afterwards, a waiting period of DRUCKAUSGLEICHZEIT_KURZ is waited for and then the starting mass (total air mass) in the single-needle system is calculated using the following formula (equation for ideal gases, isothermal):<maths id="math0003" num=""><math display="block"><mrow><mtable><mtr><mtd><mi>m</mi><mo>=</mo><mfrac><mi mathvariant="italic">pV</mi><mrow><msub><mi>R</mi><mi>S</mi></msub><mi>T</mi></mrow></mfrac></mtd><mtd><mi>m</mi><mfenced open="[" close="]"><mi mathvariant="italic">µg</mi></mfenced><mo>=</mo></mtd></mtr></mtable><mfrac><mrow><mi>p</mi><mfenced open="[" close="]"><mi mathvariant="italic">Pa</mi></mfenced><mo>⋅</mo><mi>V</mi><mfenced open="[" close="]"><msup><mi mathvariant="italic">mm</mi><mn>3</mn></msup></mfenced></mrow><mrow><msub><mi>R</mi><mi>S</mi></msub><mfenced open="[" close="]"><mfrac><mi>J</mi><mrow><mi mathvariant="italic">kg</mi><mo>⋅</mo><mi>K</mi></mrow></mfrac></mfenced><mo>⋅</mo><mi>T</mi><mfenced open="[" close="]"><mi>K</mi></mfenced></mrow></mfrac></mrow></math><img file="EP2736558B1_D0003.tif" /></maths><maths id="math0004" num=""><math display="block"><mrow><msub><mi>M</mi><mi mathvariant="italic">total</mi></msub><mo>=</mo><msub><mi>m</mi><mi mathvariant="italic">over</mi></msub><mo>+</mo><msub><mi>m</mi><mi mathvariant="italic">under</mi></msub><mo>=</mo><mfrac><mrow><msub><mi>p</mi><mi mathvariant="italic">over</mi></msub><mo>⋅</mo><msub><mi>V</mi><mi mathvariant="italic">over</mi></msub><mo>+</mo><msub><mi>p</mi><mi mathvariant="italic">under</mi></msub><mo>⋅</mo><msub><mi>V</mi><mi mathvariant="italic">under</mi></msub></mrow><mrow><mi>T</mi><mo>⋅</mo><msub><mi>R</mi><mi>S</mi></msub></mrow></mfrac></mrow></math><img file="EP2736558B1_D0004.tif" /></maths><ul id="ul0002" list-style="none"><li>R_s = spec. <maths id="math0005" num=""><math display="inline"><mrow><mi>Gas constant f</mi><mover><mi mathvariant="normal">u</mi><mrow><mo>¨</mo></mrow></mover><mi>r dry air</mi><mo>=</mo><mn>287</mn><mfrac><mi>J</mi><mrow><mi mathvariant="italic">kg</mi><mo>⋅</mo><mi>K</mi></mrow></mfrac></mrow></math><img file="EP2736558B1_D0005.tif" /></maths></li><li>P_over = Pressure in the overpressure compartment (abs.) = Measured with pressure sensor 358</li><li>P_under = Pressure in the vacuum compartment (abs.) = Measured with pressure sensor 356</li><li>V_over = Volume of overpressure compartment = 87 ml</li><li>V_under = Volume of the vacuum compartment = 308 ml</li><li>T = ambient temperature (K) = measured with temperature sensor 362</li></ul>

0156The SN compressor 350 is started with a voltage SN COMPRESSOR: VOLTAGE, which is synonymous with a compressor rate SN COMPRESSOR: RATE. In the closed system, a pressure (measured by means of the pressure sensor 358) is built up equal to or above a test pressure PRUEFDRUCK within a waiting time TIMEOUT_DP. If this pressure is successfully built up, the SN compressor 350 is stopped and the waiting time DRUCKAUSGLEICHZEIT_LANG is waited for. The air mass (M_ges (tStart)) is then calculated in the SN system after the pressure has been built up and compared with the starting mass. The mass difference M_ges_0 - M_ges (tStart) may not fall below a value DM_BUILD_FALL and may not exceed a value DM_BUILD_RISE. Otherwise the mass change in the system during the build-up of pressure is too pronounced.

0157To measure the leakage, the air mass in the system (M_ges_ (tEnd)) is recalculated after a waiting period MEASURING DURATION and compared with the starting mass at the start of the pressure maintenance test (M_ges (tStart)). The amount of the mass difference M_ges (tStart) - M_ges (tEnd) must not exceed a value DM_TEST_MAX. If it exceeds this value, the mass change in the system during the pressure maintenance test is too high.

0158An assessment of the "loss of mass" and no direct assessment of the pressure change of the respective compartments can take place due to a permissible (because it cannot be excluded) slight leakage of the SN compressor from the overpressure into the underpressure compartment.

0159At the end of the test, the bypass valve 352 is de-energized and the single-needle system is aerated by energizing the vent valve 354.

0160Examples of preset values ​​for the above parameters are given in the following parameter table (Table 7):<tables id="tabl0007" num="0007"><table frame="all"><title>Table 7</title><tgroup cols="4"><colspec colnum="1" colname="col1" colwidth="63mm" /><colspec colnum="2" colname="col2" colwidth="53mm" /><colspec colnum="3" colname="col3" colwidth="16mm" /><colspec colnum="4" colname="col4" colwidth="13mm" /><thead><row><entry valign="top"><b>Subtest</b></entry><entry valign="top"><b>parameter</b></entry><entry valign="top"><b>unit</b></entry><entry valign="top"><b>value</b></entry></row></thead><tbody><row><entry morerows="1">general parameters</entry><entry>PRINT COMPENSATION_LANG</entry><entry>s</entry><entry>5</entry></row><row><entry>PRINT COMPENSATION_Short</entry><entry>s</entry><entry>1</entry></row><row><entry morerows="1">"Establish starting conditions"</entry><entry>OFFSET_MAX</entry><entry>mbar</entry><entry>47</entry></row><row><entry>TIMEOUT_INIT</entry><entry>s</entry><entry>10</entry></row><row><entry morerows="2">"Test pressure build-up for leak testing"</entry><entry>SN COMPRESSOR: TENSION</entry><entry>V</entry><entry>4</entry></row><row><entry>TEST PRINT</entry><entry>mbar</entry><entry>950</entry></row><row><entry>TIMEOUT_DP</entry><entry>s</entry><entry>60</entry></row><row><entry morerows="1">"Mass change after pressure build-up"</entry><entry>DM_BUILD_FALL</entry><entry>mg</entry><entry>-15</entry></row><row><entry>DM_BUILD_RISE</entry><entry>mg</entry><entry>10</entry></row><row><entry morerows="1">"Mass change in the pressure maintenance phase"</entry><entry>MEASURING DURATION</entry><entry>s</entry><entry>15</entry></row><row><entry>DM_TEST_MAX</entry><entry>mg</entry><entry>1,5</entry></row></tbody></tgroup></table></tables>

0161Errors that occur in the present test and suggestions for their correction are shown in the following error table (Table 8):<tables id="tabl0008" num="0008"><table frame="all"><title>Table 8</title><tgroup cols="2"><colspec colnum="1" colname="col1" colwidth="63mm" /><colspec colnum="2" colname="col2" colwidth="103mm" /><thead><row><entry valign="top"><b>Subtest</b></entry><entry valign="top"><b>error</b></entry></row></thead><tbody><row rowsep="0"><entry morerows="3" rowsep="1">"Establish starting conditions"</entry><entry>TIMEOUT_INIT reached</entry></row><row rowsep="0"><entry>→ Valve 354 does not open (correctly) or</entry></row><row rowsep="0"><entry>→ Bypass valve 352 does not open (correctly) or</entry></row><row><entry>→ Offset of the pressure sensors too large (sensors defective)</entry></row><row rowsep="0"><entry morerows="4" rowsep="1">"Test pressure build-up for leak testing"</entry><entry>TIMEOUT_DP reached</entry></row><row rowsep="0"><entry>→ the test pressure could not be built up</entry></row><row rowsep="0"><entry> → Valve 354 not closed / leaking or</entry></row><row rowsep="0"><entry> → Bypass valve 352 not closed or</entry></row><row><entry> → Single needle valve 35 not closed</entry></row><row rowsep="0"><entry morerows="7" rowsep="1">"Mass change after pressure build-up"</entry><entry>DM_BUILD_FALL reached</entry></row><row rowsep="0"><entry>→ The mass change in the system during pressure build-up was too high</entry></row><row rowsep="0"><entry> → Valve 354 leaks or</entry></row><row><entry> → Single needle valve 35 not closed</entry></row><row rowsep="0"><entry>DM_BUILD_RISE reached</entry></row><row rowsep="0"><entry>→ The mass change in the system during pressure build-up was too high</entry></row><row rowsep="0"><entry> → Tank leaks grossly or</entry></row><row><entry> → Level of the SN chamber too high</entry></row><row><entry>"Mass change in</entry><entry>DM_TEST_MAX exceeded</entry></row><row rowsep="0"><entry>Pressure holding phase "</entry><entry>→ Mass change in the system too high during the pressure maintenance test</entry></row><row rowsep="0"><entry /><entry> → Tank leaks and / or</entry></row><row><entry /><entry> → SN chamber is leaking</entry></row></tbody></tgroup></table></tables>

0162The <b>fifth</b> Embodiment relates to a function test of the check valve 23 in the substituate channel. This test may be part of the leak test of the first embodiment discussed above, as described for the first embodiment. It is checked whether the check valve 23 is functional in the substituate channel. A pressure previously built up in EB 1 must not drop despite the backward-running substituate pump 17. This test advantageously prevents the migration of blood into the substituate channel and the contamination of the automatic substituate connector 18b (an online connector) with blood.

0163If the test is not passed, it can be repeated once. Treatment of the patient is only possible if the test is passed.

0164For details on this method, which can also be carried out separately from other tests, reference is made to the above description thereof.

0165The <b>sixth</b> Embodiment relates to a function test of the single-needle (SN) pneumatic system.

0166This test checks whether the single-needle compressor is running, whether the pneumatic valves are switching, the pressure sensors are working and whether the pneumatic system on the machine side is tight.

0167For this purpose, a pressure gradient is built up in the single-needle system when the disposable is inserted and pressed, and if necessary after a successfully completed T1 test. It is checked whether the pressure gradient is maintained within a predetermined time or at least does not drop more than allowed.

0168If this test is not passed, it is provided in certain embodiments according to the invention to prevent single-needle operation.

0169If a blood alarm occurs during the test of any embodiment according to the invention, the current test step is terminated. After the alarm has been eliminated, it is provided in some embodiments according to the invention that the aborted test is repeated automatically.

0170If an error message of the test step is present when the alarm occurs, in some embodiments according to the invention this is automatically deleted when the test step is repeated.

0171If no substituate is available (conductivity / temperature alarm), the test or partial test is also terminated in certain embodiments and then triggered again.

0172If the conductivity LF is outside a tolerance range, no substituate is made available in some embodiments according to the invention.

0173If the level in the venous chamber drops during a test, the test is terminated in certain embodiments according to the invention. An exception to this can be the leak test for the substituate connection.

0174If one of the functional tests is not passed, a confirmable alarm is generated in the event that an arterial optical detector (OD) indicates dark "(= blood enters the extracorporeal blood circuit). If an OD (venous) is located in the venous section, it is dark ", the disposable is to be dismantled.

0175The tests and subtests of the above-described embodiments can be combined with one another as required, provided that and to the extent that the person skilled in the art does not recognize this as technically impossible.

0176An appropriately programmed or configured function test monitor is used to ensure that the relevant function tests are carried out before the start of each treatment and errors are identified. This monitors the execution of the function tests and checks their results.

0177In some embodiments according to the invention, the method according to the invention comprises, in addition to the actual - e.g. B. as described above - functional tests also the determination of the system offset of the fistula pressure sensors.

0178If, when the arterial optical detector (OD) changes to dark "(= blood enters the extracorporeal blood circulation), it is recognized that a functional test has not been carried out or has not been carried out successfully, a corresponding blood alarm is issued in some embodiments according to the invention be resettable in order to be able to bridge any short-term disturbances of the arterial OD by air bubbles or the like, but this is not always provided. The bridging period can be, for example, 0.25 s. If the arterial OD remains dark, no treatment is possible in certain embodiments according to the invention.

0179In addition, if a functional test has not been passed when the venous OD detects blood, an unconfirmed blood alarm is generated which forces the system to be disarmed.

0180The procedure for monitoring the SN system function test can differ, in particular. If this is recognized as not passed (or not executed) when the venous OD changes to "dark", SN treatment is prevented by setting a corresponding variable (e.g. E2_SN_Enable to SECURE_FALSE). When the arterial OD changes to "dark", no check takes place in some embodiments according to the invention.

0181If test errors occur, status and error variables can be set. Regardless of this, entries can be made in error tables or logs. In both cases, the test carried out and the error condition, in particular readable, can be stored.

0182If the functional tests are not completed when the target flush volume is reached, the target flush volume is automatically increased by 50 ml in some embodiments according to the invention. A corresponding message can be issued.

0183If a function test is passed and / or not passed, appropriate messages can be issued.

Reference list

0184<dl id="dl0003" compact="compact"><dt>1</dt><dd>extracorporeal blood circulation</dd><dt>2</dt><dd>Blood cassette</dd><dt>3</dt><dd>first fluid guidance of the automatic substituate connector 18b</dd><dt>4</dt><dd>Treatment device</dd><dt>5</dt><dd>second fluid flow of the automatic substituate connector 18b</dd><dt>6</dt><dd>arterial patient hose clamp</dd><dt>7</dt><dd>venous patient hose clamp</dd><dt>8</dt><dd>arterial patient tube or arterial blood line</dd><dt>9</dt><dd>venous patient tube or venous blood line</dd><dt>10</dt><dd>third fluid guidance of the automatic substituate connector 18b</dd><dt>11</dt><dd>Blood pump</dd><dt>11'</dt><dd>Blood pump braking device</dd><dt>13</dt><dd>Substitution fluid addition point (predilution)</dd><dt>14</dt><dd>Substitution fluid addition point (postdilution)</dd><dt>15</dt><dd>arterial air-blood detector</dd><dt>17</dt><dd>Substituate pump</dd><dt>17'</dt><dd>Braking device of the substituate pump</dd><dt>18a</dt><dd>automatic substituate port</dd><dt>18b</dt><dd>automatic substituate connector</dd><dt>19</dt><dd>Blood filter</dd><dt>19a</dt><dd>Blood chamber</dd><dt>19b</dt><dd>Dialysate chamber</dd><dt>21</dt><dd>venous air separation chamber</dd><dt>23</dt><dd>Check valve of the substituate channel</dd><dt>25</dt><dd>venous air-blood detector</dd><dt>26</dt><dd>Compressed air source</dd><dt>27</dt><dd>Blood inlet of the blood filter 19</dd><dt>28</dt><dd>Control and / or regulating device</dd><dt>29</dt><dd>Blood outlet of the blood filter 19</dd><dt>31a</dt><dd>Dialysis fluid supply line</dd><dt>31b</dt><dd>Dialysate drain line</dd><dt>33a, b</dt><dd>Pressure sensors</dd><dt>33c</dt><dd>Prefilter pressure sensor</dd><dt>35</dt><dd>Single needle valve</dd><dt>37</dt><dd>Pressure sensor</dd><dt>40</dt><dd>Hydraulic balancing chamber</dd><dt>41</dt><dd>Dialysate inlet of the blood filter 19</dd><dt>43</dt><dd>Dialysate outlet of the blood filter 19</dd><dt>45</dt><dd>Drain line</dd><dt>47</dt><dd>Sterile air supply</dd><dt>V19</dt><dd>Dialysate drain line valve 31b</dd><dt>V24</dt><dd>Dialysis fluid supply line valve 31a</dd><dt>V25</dt><dd>Dialysate drain line valve 31b</dd><dt>V28</dt><dd>Drain line valve 45</dd><dt>V31</dt><dd>Valve of the first fluid guide 3 of the automatic substituate connector 18b</dd><dt>V32</dt><dd>Valve of the second fluid guide 5 of the automatic substituate connector 18b</dd><dt>V33</dt><dd>first valve of drain line 45</dd><dt>V42</dt><dd>Sterile air supply valve 47</dd><dt>V43</dt><dd>Valve of the third fluid guide 10 of the automatic substituate connector 18b</dd><dt>H33</dt><dd>Flushing port</dd><dt>P03</dt><dd>Ultrafiltration pump</dd><dt>100</dt><dd>Air distribution plate</dd><dt>200</dt><dd>Pneumatic unit</dd><dt>300</dt><dd>Single needle unit</dd><dt>301</dt><dd>Ventilation</dd><dt>350</dt><dd>Single-needle compressor</dd><dt>352</dt><dd>Bypass valve</dd><dt>354</dt><dd>Vent valve</dd><dt>356</dt><dd>Pressure sensor</dd><dt>358</dt><dd>SN line pressure sensor</dd><dt>360</dt><dd>Absolute pressure sensor</dd><dt>362</dt><dd>Temperature sensor in the SN pressure vessel</dd><dt>370</dt><dd>Connector, connects the single-needle unit 300 to the single-needle chamber of blood cassette 2</dd></dl>