Method for filling a membrane
AssigneeFresenius Medical Care Deutschland GmbH
InventorJoachim Noack
Life of this patent
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Abstract
A method for filling a membrane filter of a blood treatment system is provided. The blood treatment system includes at least one blood treatment machine, a membrane filter, in particular a hollow fiber membrane filter, having a first and a second chamber which are semi-permeably separated by a membrane, and at least one first partial circuit and at least one second partial circuit. The first chamber of the membrane filter is arranged in the first partial circuit and the second chamber of the membrane filter is arranged in the second partial circuit. The first chamber of the membrane filter is filled with liquid via the first partial circuit, whilst the second chamber is still filled with air, and a pump is arranged in the first partial circuit upstream of the membrane filter.
Claims20
A method of filling a membrane filter of a blood treatment system, wherein the blood treatment system has at least one blood treatment machine, a membrane filter, wherein the membrane filter is a hollow fiber membrane filter, having a first and a second chamber that are semipermeably separated by a membrane, and at least one first partial circuit and at least one second partial circuit, wherein the first chamber of the membrane filter is arranged in the first partial circuit and the second chamber of the membrane filter is arranged in the second partial circuit, wherein filling the first chamber of the membrane filter with liquid via the first partial circuit takes place while the second chamber is still filled with air, wherein the first partial circuit is a dialyzate circuit and/or the second partial circuit is an extracorporeal blood circuit, and wherein a pump having a delivery rate is arranged upstream of the membrane filter in the first partial circuit, and wherein the method comprises:
- operating the pump to begin filling the first chamber with liquid while the second chamber is still filled with air;
- measuring the pressure in the first partial circuit with a first pressure sensor and sending a first pressure signal from the first pressure sensor to a control unit;
- evaluating the first pressure signal with the control unit;
- controlling the pump for filling the first chamber in dependence on the pressure measured in the first partial circuit and/or on a transmembrane pressure, the controlling of the pump resulting in air present in the first chamber during the filling of the first chamber with liquid being displaced via the membrane into the second chamber and thus into the second partial circuit,
- controlling the pump with the control unit, to completely stop the pump, as soon as the pressure in the first partial circuit exceeds, and/or the transmembrane pressure exceeds, a first threshold value that is programmed into the control unit, while some air remains present in the first chamber,
- controlling the pump with the control unit, to start the pump again, from stop, as soon as the pressure in the first partial circuit falls below, and/or the transmembrane pressure falls below, a second threshold value that is programmed into the control unit, wherein an absolute value of the first threshold value is greater than an absolute value of the second threshold value, wherein the starting the pump again from stop again displaces air from the first chamber, via the membrane, into the second partial circuit,
- repeating the steps of controlling the pump to completely stop the pump and controlling the pump to start the pump again from stop, until the first chamber is filled with the liquid and no air is again displaced from the first chamber, via the membrane, into the second partial circuit, while the second partial circuit is not yet filled with liquid, and
- filling the second chamber with liquid after the first chamber is filled with liquid.
A blood treatment machine to which a membrane filter is coupled, the membrane filter being a hollow fiber membrane filter having a first chamber and a second chamber that are semipermeably separated from one another by a membrane, said blood treatment machine comprising:
- at least one first pump actuator of a first pump having a delivery rate for pumping liquid in a first partial circuit and at least one second pump actuator of a second pump for pumping liquid in a second partial circuit, wherein the first chamber of the membrane filter is arranged in the first partial circuit, the second chamber of the membrane filter is arranged in the second partial circuit, and the first pump is arranged upstream of the membrane filter in the first partial circuit;
- at least one first pressure sensor for measuring a pressure in the first partial circuit;
- and
- a control unit that evaluates signals of the at least one first pressure sensor and controls the at least one first pump actuator based on the signals evaluated,
- wherein the control unit is programmed with a filling program that carries out a control of the first pump actuator for filling the first chamber of the membrane filter via the first partial circuit, in dependence on the pressure measured in the first partial circuit and/or a measured transmembrane pressure, such that
- air present in the first chamber during the filling of the first chamber of the membrane filter with liquid is displaced via the membrane into the second chamber of the membrane filter and thus into the second partial circuit,
- the first pump is completely stopped as soon as the pressure in the first partial circuit and/or the transmembrane pressure exceeds/exceed a first threshold value that is programmed into the control unit, while some air remains present in the first chamber,
- the first pump is started again from stop as soon as the pressure in the first partial circuit and/or the transmembrane pressure falls/fall below a second threshold value that is programmed into the control unit, wherein an absolute value of the first threshold value is greater than an absolute value of the second threshold value,
- upon the controlling the pump with the control unit, to start the pump again from stop, air is again displaced from the first chamber, via the membrane, into the second partial circuit,
- the steps of controlling the pump to completely stop the pump and controlling the pump to start the pump again from stop, are repeated until the first chamber is filled with the liquid and no air is again displaced from the first chamber, via the membrane, into the second partial circuit, while the second partial circuit is not yet filled with liquid, and
- subsequently, after the filling of the first chamber with liquid, the second chamber is filled with liquid.
Dependencies are inferred from the claim text.