Automatic emptying of a dialyzer following a blood treatment therapy

Patent metadata

Field	Value
Publication number	US-2023372595-A1
Application number	US-202118030303-A
Country	US
Kind code	A1
Filing date	Oct 1, 2021
Priority date	Oct 7, 2020
Publication date	Nov 23, 2023
Grant date	—

Abstract

An extracorporeal blood treatment apparatus includes an extracorporeal circuit, a dialysis fluid circuit, and a dialyzer. A blood side and a dialysis fluid side of the dialyzer are separated by a membrane. A control unit automatically empties the dialyzer by setting a reduced pressure or negative pressure in the dialysis fluid circuit and by a passage of fluid from the blood side to the dialysis fluid side via the membrane. Once fluid has passed from the blood side to the dialysis fluid side and the blood side has been emptied, the control unit brings about a passage of air from the blood side to the dialysis fluid side via the membrane, and a displacement of the fluid out of the dialysis fluid side toward a dialysis fluid outflow by continued setting of the reduced pressure or negative pressure in the dialysis fluid circuit.

First claim

1 . An extracorporeal blood treatment device for use in a blood treatment therapy, the extracorporeal blood treatment device comprising:
an extracorporeal circuit; a dialysis liquid circuit; a dialyzer comprising a blood side fluidically connected to the extracorporeal circuit and a dialysis liquid side fluidically connected to the dialysis liquid circuit; and a control unit, the blood side and the dialysis liquid side being separated from each other via a membrane provided in the dialyzer, and the control unit being configured to automatically empty the dialyzer after an end of the blood treatment therapy by setting a negative pressure in the dialysis liquid circuit and a concomitant transfer of a liquid from the blood side via the membrane into the dialysis liquid side, and the control unit is being configured, when the liquid has completely transferred from the blood side via the membrane into the dialysis liquid side and the blood side of the dialyzer has been emptied, to cause, by a continued setting of the negative pressure in the dialysis liquid circuit, a transfer of air from the blood side via the membrane to the dialysis liquid side and a displacement of the liquid out of the dialysis liquid side of the dialyzer to a dialysis liquid outflow, in order to also automatically empty the dialysis liquid side of the dialyzer.

2 . The extracorporeal blood treatment device according to claim 1 , wherein the dialyzer is arranged or oriented on the extracorporeal blood treatment device during automatic emptying of the dialyzer such that a dialysis liquid exit connected to the dialysis liquid outflow is arranged below a dialysis liquid inlet connected to a dialysis liquid inflow.

3 . The extracorporeal blood treatment device according to claim 1 , wherein the control unit is configured to generate the negative pressure in the dialysis liquid circuit such that a flux-pump outlet, which is a fluid pump in the dialysis liquid outflow of the dialysis liquid circuit, is driven to pump the liquid or air out of the dialyzer into the dialysis liquid outflow.

4 . The extracorporeal blood treatment device according to claim 1 , wherein the control unit is configured to drive or actuate a compressor pump provided in the extracorporeal circuit to support the transfer of the liquid or air from the blood side via the membrane to the dialysis liquid side.

5 . The extracorporeal blood treatment device according to claim 1 , wherein the control unit is configured to control or regulate a transmembrane pressure of the dialyzer during automatic emptying of the dialyzer to a pressure that is greater than a predetermined value and smaller than a dialyzer-specific, maximum permissible transmembrane pressure.

6 . The extracorporeal blood treatment device according to claim 5 , wherein the control unit is configured to control or regulate the transmembrane pressure of the dialyzer to a pressure greater than 400 mmHg.

7 . The extracorporeal blood treatment device according to claim 1 , wherein the control unit is configured to stop automatic emptying of the dialysis liquid side of the dialyzer in a sensor-controlled manner.

8 . The extracorporeal blood treatment device according to claim 7 , wherein the control unit is configured to:
evaluate a pressure signal or pressure course of a pressure sensor arranged in the dialysis liquid outflow, the pressure sensor configured to measure or monitor a pressure in the dialysis liquid outflow, and stop the automatic emptying of the dialysis liquid side based on the pressure signal or pressure course of the pressure sensor.

9 . The extracorporeal blood treatment device according to claim 8 , wherein the control unit is configured to:
evaluate a slope or a first derivative of the pressure signal or pressure course of the pressure sensor, and stop automatic emptying of the dialysis liquid side when the slope or the first derivative of the pressure signal or pressure course falls below a predetermined first limit value.

10 . The extracorporeal blood treatment device according to claim 7 , wherein the control unit is configured to stop automatic emptying of the dialysis liquid side in a sensor-controlled manner when an air separator in the dialysis liquid circuit detects or measures that a liquid level of the air separator has fallen below a predetermined liquid level or gauge height.

11 . The extracorporeal blood treatment device according to claim 1 , wherein the control unit is configured to stop automatic emptying of the dialysis liquid side of the dialyzer in a time-controlled manner.

12 . A method for automatically emptying a dialyzer after an end of a blood treatment therapy comprising the steps of:
setting a negative pressure in a dialysis liquid circuit and concomitant transfer of a liquid from a blood side of the dialyzer via a membrane of the dialyzer into a dialysis liquid side of the dialyzer; and continuing to set the negative pressure in the dialysis liquid circuit when the liquid from an extracorporeal circuit has completely passed from the blood side via the membrane of the dialyzer into the dialysis liquid side and the blood side of the dialyzer has been emptied, so as to cause a transfer of air from the blood side via the membrane of the dialyzer to the dialysis liquid side and a displacement of liquid out of the dialysis liquid side of the dialyzer to a dialysis liquid outflow in order to also automatically empty the dialysis liquid side of the dialyzer.

Assignees

• Braun Avitum Ag

Inventors

• Schiller Joana Sophie
• Wuerschmidt Tobias

Classifications

• A61M1/365 Primary

  through membranes, e.g. by inverted trans-membrane pressure [TMP] · CPC title

• A61M1/3652 Primary

  using gas, e.g. air · CPC title