A Control And/Or Closed-Loop Control Device For Removing Fluid from A Blood Filter

Abstract

The present disclosure relates to a control and/or closed-loop control device for executing a method for removing fluid from an extracorporeal blood circuit, in particular from a blood filter and/or from a venous air separation chamber, used for the blood treatment of a patient, wherein said controlling or closed-loop controlling is carried out after the completion of the blood treatment or the blood treatment session. It further relates to a medical treatment apparatus having a control and/or closed-loop control device with which the method according to the present disclosure is executable, a digital storage medium, a computer program product and a computer program.

Claims

1. A control device configured for controlling, in interaction with a blood treatment apparatus, a method for removing blood from a blood filter or extracorporeal blood circuit used for a blood treatment of a patient after completion of the blood treatment, wherein the extracorporeal blood circuit comprises: the blood filter having a blood chamber and a dialysis chamber between which a membrane is arranged; an arterial blood line or blood withdrawal line connected to the blood chamber; a venous blood line or blood return line connected to the blood chamber; and a valve for selecting between establishing or interrupting a fluid connection between a line interior of the extracorporeal blood circuit and atmosphere at an exterior of the extracorporeal blood circuit; wherein the blood treatment apparatus comprises: at least one blood pump arranged along the extracorporeal blood circuit for conveying blood within the line interior of the extracorporeal blood circuit: at least one conveying device for introducing substituate or dialysis liquid into the arterial blood line or blood withdrawal line or into the venous blood line or blood return line; at least one venous patient hose clamp for interrupting a flow through a section of the venous blood line or blood withdrawal line; at least one actuation device for actuating the valve; and at least one pressure sensor for measuring a pressure prevailing in the arterial blood line or blood withdrawal line or in the venous blood line or blood return line; wherein the method comprises: a) interrupting a connection between the atmosphere and the line interior of the extracorporeal blood circuit by closing the valve; b) closing the at least one venous patient hose clamp; c) introducing substituate or dialysis liquid into: (i) the arterial blood line or the blood withdrawal line, or (ii) the venous blood line or the blood return line, and/or establishing an increased pressure, via a pump used for the introducing, in (i) the arterial blood line or the blood withdrawal line, or (ii) the venous blood line or the blood return line; d) establishing the fluid connection between the atmosphere/the exterior and the line interior of the extracorporeal blood circuit by opening the valve either: (i) in response to the measured pressure reaching or exceeding a predetermined first value or (ii) when a predetermined first time period has elapsed since beginning the introducing substituate or dialysis liquid since the beginning of the establishing or increasing pressure in (i) the arterial blood line or the blood withdrawal line, or (ii) the venous blood line or the blood return line with the closed at least one venous patient hose clamp; and f) interrupting the fluid connection between the atmosphere and the line interior of the extracorporeal blood circuit by closing the valve and opening the at least one venous patient hose clamp either (i) in response to the measured pressure decreasing to a predetermined second value or (ii) when a predetermined second time period has elapsed since the valve was opened in step d).

2. The control device according to claim 1, wherein the predetermined first value for the pressure is between 1 and 2 bar or the predetermined first time period is between 2 sec and 5 sec.

3. The control device according to claim 1, wherein the predetermined second value is between 0 and 0.5 bar or the predetermined second time period is between 1 sec and 3 sec.

4. The control device according to claim 1, wherein when executing the method, a free end of the arterial blood line or blood withdrawal line is connected in fluid communication to a further section of the venous blood line or blood return line.

5. The control device according to claim 1, wherein the extracorporeal blood circuit comprises a venous air separation chamber; and wherein the method begins only after it has been ascertained that the venous air separation chamber is not completely filled with liquid, or it is not filled with liquid beyond a predetermined level.

6. The closed control device according to claim 1, wherein the extracorporeal blood circuit comprises a venous air separation chamber and a single-needle chamber, and wherein the valve is arranged between the single-needle chamber and the venous air separation chamber.

7. The control device according to claim 1, wherein the steps a) to e) of the method for removing blood are performed several times in succession.

8. A medical treatment apparatus comprising: at least one extracorporeal blood circuit with a line interior and comprising an arterial blood line or blood withdrawal line; at least one blood pump arranged along the extracorporeal blood circuit for conveying blood within the line interior of the extracorporeal blood circuit; at least one conveying device for introducing substituate or dialysis liquid into the arterial blood line or blood withdrawal line; and at least one control device according to claim 1.

9. The medical treatment apparatus according to claim 8, wherein the extracorporeal blood circuit is, at least in section thereof, part of a blood cassette.

10. A digital storage medium in the form of a disk, CD, or DVD or EPROM, with electronically readable control signals, configured for configuring the control device according to claim 1.

11. A computer product with a program code saved on a machine-readable carrier for configuring the control device according to claim 1.

12. A computer program with a program code for configuring the control device according to claim 1.

13. The control device according to claim 1, wherein the method further comprises measuring, using the pressure sensor, the pressure prevailing in: (i) the arterial blood line or blood withdrawal line or (ii) the venous blood line or blood return line.

14. The control device according to claim 1, wherein the method further comprises measuring, using the pressure sensor, the pressure prevailing in: (i) the arterial blood line or blood withdrawal line and (ii) the venous blood line or blood return line.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0098] In the following, the method according to the present disclosure is described based on preferred embodiments thereof with reference to the accompanied drawing. In the drawing the following applies:

[0099] FIG. 1 shows an exemplary embodiment of schematically simplified sections of a medical treatment apparatus according to the present disclosure with a blood cassette for executing the method controlled and/or closed-loop controlled by a control and/or closed-loop control device according to the present disclosure.

DETAILED DESCRIPTION

[0100] FIG. 1 shows an extracorporeal blood circuit 1, which would be connected for a treatment to the vascular system of the patient (not shown) via double-needle access or via single-needle access using e.g. an additional Y-connector. The blood circuit 1 is provided optionally in sections thereof in or on a blood cassette 2. This blood cassette 2 is designed to be used also in other treatment types, e.g. a single-needle treatment.

[0101] Pumps, actuators, and/or valves in the area of the blood circuit 1 are connected to a treatment apparatus 4 according to the present disclosure or to a control and/or closed-loop control device 29 according to the present disclosure.

[0102] The blood circuit 1 comprises an arterial patient hose clamp 6 and an arterial connection needle 5 (as an example for an access device) of an arterial section or of an arterial patient line or blood withdrawal line 9. The blood circuit 1 further comprises a venous patient hose clamp 7 and a venous connection needle 27 (as an example for a further or second access device) of a venous section or of a venous patient line or blood return line 23.

[0103] A blood pump 11 is provided in the arterial section 9, a substituate pump 17 is connected to a substituate line 17a. The substituate line 17a can be connected with a substituate source through a, preferably automatic, substituate port 18. By means of the substituate pump 17, substituate may be introduced via pre-dilution or via post-dilution through associated lines 13 or 14 into line sections, e.g. into the arterial section 9 or into a venous section 23a (between a blood chamber 19a of a blood filter 19 and a venous air separation chamber 21), of the blood circuit 1.

[0104] The blood filter 19 comprises the blood chamber 19a which is connected to the arterial section 9 and to the venous section 23. A dialysate chamber 19b of the blood filter is connected to a dialysis liquid inlet line 31a leading to the dialysate chamber 19b and to a dialysate outlet line 31b leading away from the dialysate chamber 19b.

[0105] The dialysis liquid inlet line 31a optionally comprises a valve V24 by which the flow within the dialysis liquid inlet line 31a may be interrupted. The dialysate outlet line 31b optionally comprises a valve V25 by which the flow within the dialysate outlet line 31b may be interrupted.

[0106] The dialysis liquid inlet line 31a is further optionally connected to a compressed air source 26 by means of another internal valve of the apparatus. The compressed air source 26 may be provided as a part or component of the treatment apparatus 4 or as a part separated thereof. A pressure sensor 37 may be provided downstream of the compressed air source 26.

[0107] The fluid connection 34 indicated in FIG. 1 by a dash-dotted line represents a connection between the arterial section 9 and the venous section, here upstream of the addition site 14 for substituate (postdilution). The fluid connection 34 may, amongst others, serve the simple automatic draining of the arterial section 9 or the inlet line 8 of the extracorporeal blood circuit. The fluid connection 34 may in addition ensure that the pressure which is built up according to the present disclosure cannot unintentionally decrease via the arterial section 9.

[0108] The fluid connection 34 may be achieved by a factory-made connection section 24 with e.g. the venous section 23 or 23a. The connection section 24 may allow a fluid connection with the venous section 23 or 23a.

[0109] The fluid connection 34 may be easily achieved by disconnecting the arterial section 9 from the patient and connecting it to e.g. the venous section 23 or 23a, for example using the optional connection section 24.

[0110] To maintain the pressure, one or several different measures may be used instead of (or in addition to) the fluid connection 34. Thus, a decrease of the pressure through the arterial side of the blood circuit may be prevented for example by an occluding pump, here the blood pump 11, or by closing the arterial patient hose clamp 6.

[0111] In order to effect the method for emptying the extracorporeal blood circuit 1 from blood after the completion of the treatment, in particular to empty the blood chamber 19a of the blood filter 19, the following steps a) to f) may be executed once or several times by the control and/or closed-loop control device 29 according to the present disclosure. In this, it is assumed that it has been ensured, preferably automatically, that the venous air separation chamber 21 is only partially, i.e. not completely, filled with blood. [0112] a) interrupting a fluid connection between the venous air separation chamber 21 on the one hand and the single-needle chamber 36 (as an example for the atmosphere or the exterior) on the other hand by closing a valve, here e.g. the valve 35; [0113] b) closing the venous patient hose clamp 7 or preventing the flow along the venous blood return line 23 downstream of the blood filter 19 in a different way; [0114] c) introducing substituate or dialysis liquid into the blood circuit 1, in particular into the arterial blood withdrawal line 9 or into the venous blood return line 23; [0115] d) measuring the pressure prevailing in the arterial blood withdrawal line 9 and/or in the venous blood return line 23 using the pressure sensor (33a, 33b); [0116] e) establishing a connection between the venous air separation chamber 21 and the single-needle chamber 36 of the extracorporeal blood circuit 1 by opening the valve 35, when the measured pressure reaches or exceeds a predetermined first value; and [0117] f) interrupting a connection between the venous air separation chamber 21 and the single-needle chamber 36 of the extracorporeal blood circuit 1 by closing the valve 35 and opening the patient hose clamp 7, in both cases after the measured pressure has decreased to a predetermined second value.

[0118] In the present embodiment (double-needle method) the single-needle chamber 36 serves as a ventilation device for the venous air separation chamber 21 and represents therefore the atmosphere or the exterior.

[0119] Alternatively, it is conceivable that a valve other than the valve 35 represents a connection between the atmosphere/the exterior and the interior of the extracorporeal blood circuit 1 and thus said connection between the atmosphere/the exterior and the interior is established or interrupted by opening or closing said other valve.

[0120] Alternatively or additionally, the substituate may be introduced by the blood pump 11 and not by the substituate pump 17. For this purpose, the arterial patient hose clamp 6 is closed and substituate is introduced from a reservoir for substituate into the extracorporeal blood circuit 1 through an inlet line 8.

[0121] The control and/or the closed-loop control device 29 may be part of a control and/or closed-loop control device of the treatment apparatus 4.

[0122] The arrangement of FIG. 1 encompasses an optional detector 15 for detecting air and/or blood. The arrangement of FIG. 1 further encompasses one or two pressure sensors 33a, 33b at the illustrated points in FIG. 1.

[0123] In FIG. 1, the single-needle chamber 36 is used as buffer and/or compensation tank, in particular during or after a double-needle method by which the patient is connected to the extracorporeal blood circuit 1 via two blood lines 9, 23. It is obvious for the person skilled in the art that any other compensation tank may be taken into consideration as well.

[0124] The present disclosure is not limited to the embodiment as described above, this is considered only for illustrative purposes. Also a time regulation as described supra may be used instead of or in addition to pressure regulation as described with respect to FIG. 1. Furthermore, the disclosure is not limited to emptying the content or parts thereof while a connection with the vascular system still exists.

LIST OF REFERENCE NUMERALS

[0125] 1 extracorporeal blood circuit [0126] 2 blood cassette [0127] 4 treatment apparatus [0128] 5 access device, e.g. arterial connection needle [0129] 6 arterial patient hose clamp [0130] 7 venous patient hose clamp [0131] 8 supply line [0132] 9 arterial section or arterial blood withdrawal line or arterial patient line [0133] 11 blood pump [0134] 13 addition site for substituate (predilution) [0135] 14 addition site for substituate (postdilution) [0136] 15 arterial air/blood detector [0137] 17 second conveying device, e.g. a substituate pump [0138] 17a substituate line [0139] 18 automatic substituate port [0140] 19 blood filter [0141] 19a blood chamber [0142] 19b dialysate chamber [0143] 21 venous air separation chamber [0144] 23 venous section or venous blood return line [0145] 23a venous section [0146] 24 connection site, connection section [0147] 25 venous substituate/blood detector [0148] 26 compressed air source [0149] 27 access device, e.g. venous connection needle [0150] 29 control or closed-loop control device [0151] 31a dialysis liquid inlet line [0152] 31b dialysate outlet line [0153] 33a, b pressure sensors [0154] 34 fluid connection [0155] 35 single-needle valve [0156] 36 single needle chamber [0157] 37 pressure sensor [0158] V24 valve [0159] V25 valve