Method And Devices For The Calibration Of A Pump For The Blood Treatment

Abstract

The present disclosure relates to a method for determining an actual pump rate and/or for calibrating a blood pump of a blood treatment apparatus connected to an extracorporeal blood circuit. The method includes providing a blood pump of a blood treatment apparatus or establishing a signal communication to a blood pump. The blood pump comprises, or is connected to at least a first source for a fluid and at least a first line of an extracorporeal blood circuit which is connected to the first source downstream. Furthermore, the blood pump comprises, or is connected to, a reception unit for receiving fluids of the first source wherein the reception unit is in fluid communication with the first line. The reception unit is arranged on or at a first weighing device such that the weight of the reception unit or of its content is determined using the weighing device.

Claims

1-21. (canceled)

22. A method for determining an actual pump rate or for calibrating a blood pump of a blood treatment apparatus connected to an extracorporeal blood circuit, the method comprising: providing a blood pump of a blood treatment apparatus, or establishing a signal connection to a blood pump, the blood pump connected to or comprising: at least a first fluid source; at least a first line of an extracorporeal blood circuit which is connected downstream to the first fluid source; and at least one reception unit for receiving fluid of the first fluid source, wherein the reception unit is in fluid communication with the first line, wherein the reception unit is arranged on or at a first weighing device such that a weight of at least one of the reception unit or of a content of the reception unit is determinable via the weighing device; setting a value for a pump rate being adjustable at the blood pump as a set pump rate, or transmitting such a value to the blood pump as a set pump rate; operating the blood pump at the set pump rate during a conveyance time period such that the fluid from the first fluid source is conveyed as actual volume through the first line into the reception unit; determining via the first weighing device an actual volume conveyed during the conveyance time period based on a change of the weight of the reception unit or of the contents of the reception unit; and determining a mathematical relation between the actual volume and a target volume, the target volume resulting from the conveyance time period and the set pump rate.

23. The method according to claim 22, wherein the method further comprises: determining a relation between the set pump rate and an actual pump rate, wherein the actual pump rate is determined considering the actual volume and the conveyance time period.

24. The method according to claim 23, wherein the method further comprises: defining a correction factor or calibration factor for the blood pump based on the relation between the pump rate set at the blood pump and the actual pump rate or based on the actual volume and the target volume.

25. The method according to claim 23, wherein the method further comprises: defining a correction factor or calibration factor for the blood pump based on the relation between the pump rate set at the blood pump and the actual pump rate and based on the actual volume and the target volume.

26. The method according to claim 22, further comprising: generating the same pressure relations before and after the conveyance time period or during the conveyance time period in the first line.

27. The method according to claim 22, further comprising: generating the same pressure relations before and after the conveyance time period and during the conveyance time period in the first line.

28. The method according to claim 22, wherein the extracorporeal blood circuit comprises, or is connected to, a blood filter or a dialyzer that comprises a semi-permeable membrane.

29. The method according to claim 28, wherein the reception unit is in fluid communication with the first line downstream of the blood filter or the dialyzer.

30. The method according to claim 28, wherein the reception unit is in fluid communication with the first line downstream of the blood filter or the dialyzer and through the semi-permeable membrane of the dialyzer.

31. The method according to claim 28, wherein the blood filter or the dialyzer is connected to a dialysis liquid inlet line and a dialysate line, wherein at least one of a check valve and an occluding pump is integrated in the dialysis liquid inlet line to prevent an undesired flow in direction against a flow direction of the dialysis fluid inlet line and/or in direction away from the blood filter.

32. The method according to claim 28, wherein the blood filter or the dialyzer is in fluid communication with an arterial patient line and with a venous patient line, wherein a tube clamp is arranged in or at the venous patient line, wherein the method further comprises: closing the tube clamp at the venous patient line during the conveyance time period.

33. The method according to claim 22, wherein the blood pump and an effluent pump convey at the same pump rate during the conveyance time period.

34. The method according to claim 22, further comprising: generating same pressure relations before and after the conveyance time period or during the conveyance time period in the first line.

35. The method according to claim 34, wherein in order to generate same pressure relations, an effluent pump is rotated by a control or closed-loop device, in a pressure-controlled manner.

36. The method according to claim 22, further comprising: generating same pressure relations before and after the conveyance time period and during the conveyance time period in the first line.

37. The method according to claim 22, wherein the first fluid is a saline solution, a dialysis liquid, a substituate, or a priming liquid.

38. The method according to claim 22 further comprising: providing the blood treatment apparatus as or being a hemodialysis apparatus, hemofiltration apparatus, or hemodiafiltration apparatus.

39. A blood treatment apparatus, which comprises, or is connected to, an extracorporeal blood circuit, wherein the blood treatment apparatus further comprises, or is connected to: a blood pump, which is connectable or connected to at least one of: at least a first fluid source, and at least a first line, which is connected to the first fluid source downstream; at least one reception unit for receiving fluid of the first fluid source, wherein the reception unit is in fluid communication with the first line; a first weighing device for the reception unit; and a control or closed-loop device configured to execute a method comprising: setting a value for a pump rate as a set pump rate being adjustable at the blood pump by a user or automatically by the control or closed-loop device; operating at least one blood pump at the set pump rate during a conveyance time period such that fluid from the first fluid source is conveyed through the first line into the reception unit; determining at least one of an actual volume and an actual pump rate by the first weighing device during the conveyance time period; and determining a mathematical relation between the actual volume and a target volume resulting from the conveyance time period and the set pump rate.

40. The blood treatment apparatus according to claim 39, wherein the blood treatment apparatus is a hemodialysis apparatus, hemofiltration apparatus, or hemodiafiltration apparatus.

41. A computer program product with a program code saved on a machine-readable medium for prompting machine-induced steps of a method when the computer program product runs or is executed on a computer, the method comprising: setting a value for a pump rate being adjustable at a blood pump as a set pump rate, or transmitting such a value to the blood pump as a set pump rate; operating the blood pump at the set pump rate during a conveyance time period such that a fluid from a first source is conveyed as actual volume through a first line into a reception unit; determining via a first weighing device an actual volume conveyed during the conveyance time period based on a change of a weight of the reception unit or of the contents of the reception unit; and determining a mathematical relation between the actual volume and a target volume, the target volume resulting from the conveyance time period and the set pump rate.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0063] In the following, the present invention is merely exemplarily described with regard to the enclosed drawings, in which identical reference numerals refer to the same or similar components. The following applies:

[0064] FIG. 1 shows a simplified illustration of a blood treatment apparatus with an extracorporeal blood circuit in a first embodiment;

[0065] FIG. 2 shows a simplified illustration of a blood treatment apparatus with an extracorporeal blood circuit in a second embodiment; and

[0066] FIG. 3 shows a simplified illustration of a blood treatment apparatus with an extracorporeal blood circuit in a third embodiment.

DETAILED DESCRIPTION OF THE FIGURES

[0067] FIG. 1 shows a simplified illustration of a blood treatment apparatus 100 connected to an extracorporeal blood circuit 300 during the execution of the method described herein. FIG. 1 shows the basic principle.

[0068] The extracorporeal blood circuit 300 comprises a first line 301, here being an arterial line section.

[0069] The first line 301 is in fluid communication with a blood treatment device, here exemplarily a blood filter 303 or a dialyzer. The blood filter 303 comprises a dialysis liquid chamber 303a and a blood chamber 303b which are separated from each other by a mostly semi-permeable membrane 303c.

[0070] The extracorporeal blood circuit 300 further comprises at least a second line 305, here being a venous line section. Both the first line 301 and the second line 305 may serve for the connection to the vascular system of the patient, not shown.

[0071] The blood treatment apparatus 100, represented in FIG. 1 only through some of its devices by means of which the method, described herein, is executed, comprises a blood pump 101. During the treatment of the patient, the blood pump 101 conveys blood through sections of the extracorporeal blood circuit 300 and in direction towards the blood filter 303, as the small arrow tips show, which generally indicate the flow direction in the figures.

[0072] For calibrating the blood pump 101, fluid from a first source 200 is pumped by a blood pump 101, which may optionally be embodied as a roller pump or as any other occluding pump, along the first line 301 in direction of the reception unit 400.

[0073] The source 200 may be, for example, a bag or a container. The same applies for the reception unit 400. The source 200 may further be a fluid line, from which online and/or continuously produced or mixed liquid is provided, for example, a hydraulic outlet or hydraulic port of the blood treatment apparatus

[0074] The reception unit 400 is connected to a first weighing device 141 for weighing the weight of the reception unit 400 or of the fluid received therein or for determining a weight change. For example, the reception unit 400 may be disposed as a collecting bag on a weighing surface of the first weighing device 141 or may hang on a weighing hook.

[0075] If the blood pump 101 now conveys over a predetermined or determinable time period, namely the conveyance time period T then, based on the pump rate P1 of the blood pump 101 determined by the user or by a test program and the conveyance time period T, the volume of the fluid which should have been conveyed, if the blood pump 101 would indeed convey at the predetermined pump rate P1, may be determined by the simple relation P1*T=VS.

[0076] In practice, the actually conveyed volume, which is herein referred to as actual volume VI may deviate from the target volume.

[0077] The actual volume VI is however found again in the reception unit 400 after termination of the conveyance time period T. The actual volume can be determined based on the weight measurement, which is herein exemplarily carried out by the first weighing device 141; the weight of the actual volume corresponds to the increase of the weight of the reception unit between a measurement made before the beginning of the conveyance time period T and a measurement made at a point of time which is after the conveyance time period T.

[0078] A comparison of the measured actual volume VI with the calculated target volume VS may serve for calculating a correction factor or a calibration value of the set pump rate or of the blood pump 101.

[0079] A control or closed-loop device 150, first described and shown in FIG. 2 (see FIG. 2), may be configured to execute the foregoing method. Optionally, an automatic execution takes place. Optionally, the execution starts automatically, for example within a test function, a self-check when starting the blood treatment apparatus during or following a priming process, etc.

[0080] FIG. 2 shows a simplified illustration of a blood treatment apparatus 100 with an extracorporeal blood circuit 300 in a second embodiment.

[0081] In addition to the aforementioned blood pump 101, the arrangement shown in FIG. 2 further comprises a number of other, each being optional, pumps, i.e. the pump 111 for substituat, the pump 121 for dialysis liquid and the pump 131 for dialysate and/or effluent.

[0082] The pump 121 is provided to pump dialysis liquid out of a source Q4, for example, a bag, and to convey said dialysis liquid via a dialysis liquid inlet line 104 through an optionally available bag heating with a bag H2.

[0083] The dialysis liquid conveyed in this way, leaves again through a dialysate line 102, supported by the pump 131, and may be discarded.

[0084] An optional arterial sensor PA1 is provided upstream of the blood pump 101. Sensor PA1 measures the pressure in the arterial line during a treatment of a patient.

[0085] A further optional pressure sensor PA2 is provided downstream of the blood pump 101, however upstream of the blood filter 303 and, if provided, upstream of an addition site 25 for heparin. Pressure sensor PA2 measures the pressure upstream of the blood filter 303 (pre-hemofilter).

[0086] An again further pressure sensor may be provided as PD1 downstream of the blood filter 303, however preferably upstream of the pump 131 in the dialysate line 102, to measure a filter pressure downstream of the blood filter 303.

[0087] Blood, which leaves the blood filter 303, flows through or perfuses an optional venous blood chamber 29, which may comprise an optional closable ventilation device 31 and which may be in fluid communication with a further pressure sensor PV1.

[0088] In the example of FIG. 2, the source Q4 and an optional further source Q4, out of which substituat is collected via the pump 111 through a further bag heating with bag H3, as well as the caught or discarded dialysate are optionally subject to balancing. For the purpose of balancing, two further optional weighing devices 142 and 143 are provided in addition to the first weighing device 141 known from FIG. 1.

[0089] The balancing shown herein exemplarily corresponds to a gravimetric balancing, but may also encompass any other balancing, for example using balancing chambers.

[0090] The arrangement shown exemplarily in FIG. 2 comprises a control or closed-loop device 150. for controlling the blood treatment apparatus 100 It may be in a wired or wireless signal communication with each of the components mentioned hereinin any case or in particular with the blood pump 101. It may be optionally configured to execute the method described herein.

[0091] The first line 301 is optionally connected to tube clamp 302 for locking or closing the line 301. The second line 305 is optionally connected to a tube clamp 306 for locking or closing the line 305.

[0092] Even though the embodiment of FIG. 2 is shown with a reception unit 400 for fluid the weight of which is determined by the first weighing device 141, wherein the reception unit 400 may be arranged to the blood side due to its fluid communication with the blood circuit, here downstream of the blood filter 303.

[0093] However, the reception unit may alternatively be arranged on the hydraulic side or filtrate side (i.e., not on the blood side, rather in the area of the component 102 and 131). In this way, the reception unit may be weighed by a third weighing device 143, as indicated with the reference numeral 400.

[0094] FIG. 3 shows a simplified illustration of a blood treatment apparatus 100 with an extracorporeal blood circuit 300 in a third embodiment.

[0095] The illustration of FIG. 3 differs from that of FIG. 2 already by the fact that a number of components, which are shown in FIG. 2 for the sake of clarity, are not shown again in FIG. 3. However, they may also optionally be present here.

[0096] The embodiment shown in FIG. 3 differs however from that of FIG. 2 in that an optional check valve 104a is arranged in the dialysis liquid inlet line 104. The check valve 104a opens at a corresponding high pressure to enable a flow through the dialysis liquid inlet line 104 in direction of the blood filter 303. However, the check valve 104a prevents a flow in the opposite direction through the dialysis liquid inlet line 104.

[0097] In the embodiment of FIG. 3, the blood pump 101 conveys fluid from the source 200 into the blood filter 303. Since the tube clamp 306 of the second line 305 is closed, the fluid conveyed passes through the membrane 303c from the blood chamber 303b into the dialysis liquid chamber 303a. The check valve 104aor another occluding device, for example, a roller pump instead of the check valve or in addition theretoprevents that the fluid passing into or through the dialysis liquid chamber 303a leaves the latter through a line other than the line 102. Conveying the fluid along the aforementioned path is ensured by the pumping function of the pump 131, the effluent pump, inserted into the dialysate line 102. Finally, the fluid is forwarded into the reception unit 400 whose weight change may be determined by the third weighing device 143. As a result, the actual volume VI, which was conveyed by the blood pump 101 during the conveyance time period T, is obtained.

[0098] The following features, although not shown in the figures, may again in each embodiment be purely optional and provided in any combination:

[0099] The first line 301 may comprise an arterial septum, optionally in form of an addition device.

[0100] The first line 301 and/or the second line 305 may comprise an air bubble detector/optical sensor.

[0101] The blood circuit may at least partially comprise, be or be connected to, part of a blood cassette, which comprises a hard part covered completely or partially by a film.

LIST OF REFERENCE NUMERALS

[0102] 25 addition site for heparin (optional) [0103] 29 venous blood chamber (optional) [0104] 31 ventilation device [0105] 100 blood treatment apparatus [0106] 101 blood pump [0107] 102 dialysate line [0108] 104 dialysis liquid inlet or supply line [0109] 104a check valve [0110] 111 pump for substituat [0111] 121 pump for dialysis liquid [0112] 131 pump for dialysate and/or effluent [0113] 141 first weighing device [0114] 142 second weighing device [0115] 143 third weighing device [0116] 150 control or closed-loop device [0117] 200 fluid source [0118] 300 extracorporeal blood circuit [0119] 301 first line (arterial line section) [0120] 302 tube clamp [0121] 303 blood filter or dialyzer [0122] 303a dialysis liquid chamber [0123] 303b blood chamber [0124] 303c semi-permeable membrane [0125] 305 second line (venous line section) [0126] 306 tube clamp [0127] 400 reception unit for fluid [0128] 400 reception unit for fluid [0129] H2 bag heater with bag (dialysis liquid) [0130] H3 bag heating with bag (substituate) [0131] PA1, PA2 arterial pressure sensor (optional) [0132] PD1 pressure sensor for measuring the filter pressure [0133] PV1 pressure sensor (optional) [0134] P1 set pump rate [0135] Q4 source with dialysis liquid [0136] Q4 source (substituate), optional [0137] T conveyance time period [0138] VI actual volume [0139] VS target volume