Weight-based systems for use in extracorporeal blood treatment

2:

• The device of claim 1, wherein the processor circuitry is configured to estimate the time profile by performing a linear interpolation of the first and second values.

3:

• The device of claim 1, wherein the pumping parameter is one of:
• a flow rate generated by the pumping device or a stroke volume of the pumping device.

4:

• The device of claim 1, wherein the pumping parameter is a stroke volume of the pumping device, and wherein the processor circuitry is further configured to receive, via the input interface, a further measurement signal representative of a speed of the pumping device, and determine the first and second values of the pumping parameter based on the measurement signal and the further measurement signal during the first and second measurement period, respectively.

5:

• The device of claim 4, wherein the processor circuitry is further configured to:
• determine a fluid flow parameter for the level adjustment period, based on the time profile and the further measurement signal during the level adjustment period, and determine the ultrafiltration parameter based on the fluid flow parameter.

6:

• The device of claim 5, wherein the fluid flow parameter represents a total amount of the fluid pumped by the pumping device during the level adjustment period.

7:

• The device of claim 6, wherein the processor circuitry is configured to:
• determine, based on the further measurement signal, a count of pumping strokes performed by the pumping device during the level adjustment period, calculate an average stroke volume for the level adjustment period based on the time profile, and determine the fluid flow parameter as a function of the average stroke volume and the count of the pumping strokes.

8:

• The device of claim 4, wherein the further measurement signal comprises a predefined number of pulses for each pumping stroke of the pumping device.

9:

• The device of claim 1, wherein the ultrafiltration parameter comprises an amount of ultrafiltrate extracted from the blood in the dialyzer.

10:

• The device of claim 1, wherein the processor circuitry is configured to:
• receive, via the input interface, an input signal which is representative of fluid pressure in the first fluid path between the container and the pumping device or which is representative of a control signal for the pumping device, and
• estimate the time profile based on the first and second values and the input signal during the level adjustment period.

12:

• The device of claim 1, wherein the processor circuitry is further configured to:
• monitor the measurement signal for detection of a step-change during the level adjustment period, and
• to initiate, upon detection of the step-change, a dedicated action.

13:

• The device of claim 12, wherein the dedicated action comprises one or more of:
• a modification of the level adjustment period, accounting for the step-change when estimating the time profile of the pumping parameter, or a modification of a pumping speed of the pumping device.

14:

• The device of claim 13, wherein the modification of the level adjustment period results in a stop of the level adjustment.

15:

• The device of claim 13, wherein the processor circuitry is configured to, upon the detection of the step-change, determine a magnitude of the step-change, wherein the dedicated action uses the magnitude.

16:

• The device of claim 15, wherein the modification of the pumping speed is based on the magnitude to at least partly compensate for a change in flow rate in the first fluid path resulting from the step-change.

17:

• The device of claim 15, wherein the processor circuitry is configured to estimate the time profile of the pumping parameter based on the first and second values, the magnitude, and a timing of the step-change during the level adjustment period.

18:

• The device of claim 12, wherein the processor circuitry is configured to generate, based on the measurement signal, a monitoring signal that represents momentary change of the weight of the container, and detect the step-change in the monitoring signal.

19:

• The device of claim 12, wherein the pumping device, when operated at the known setting, is configured to repeatedly generate a temporal variation in fluid flow rate in the first fluid path, and wherein the processor circuitry is configured to detect the step-change as a momentary change in an amplitude of the temporal variation as embedded in the measurement signal.

20:

• The device of claim 19, wherein the processor circuitry is configured to generate, based on the measurement signal, a monitoring signal that represents a momentary change of the weight of the container, and detect the step-change based on the monitoring signal.

21:

• The device of claim 20, wherein the processor circuitry is configured to generate the monitoring signal to represent a derivative of the measurement signal.

22:

• The device of claim 20, wherein the processor circuitry is configured to generate a difference signal by subtracting a representation of the temporal variation from the monitoring signal and detect the step-change in the difference signal.

23:

• The device of claim 22, wherein the processor circuitry is configured to process the difference signal for detection of the temporal variation, wherein the step-change is detected by presence of the temporal variation in the difference signal.

24:

• The device of claim 19, wherein the temporal variation comprises a minimum flow rate and a maximum flow rate.

25:

• The device of claim 24, wherein a difference between the minimum flow rate and the maximum flow rate is at least twice an average flow rate generated by the pumping device when operated at the known setting.

26:

• The device of claim 19, wherein the temporal variation is a sinusoidal variation.

27:

• The device of claim 19, wherein the temporal variation results in a sequence of time-separated pulses of increased flow rate.

28:

• The device of claim 27, wherein the temporal variation corresponds to an intermittent activation of the pumping device.

29:

• The device of claim 1, wherein the fluid in the container is fresh dialysis fluid for use in the extracorporeal treatment of blood in the dialyzer, or water that is mixed with one or more concentrates in the first fluid path to form the fresh dialysis fluid, and wherein the first dialyzer port is an inlet port for the fresh dialysis fluid.

30:

• The device of claim 1, wherein the fluid in the container is spent dialysis fluid resulting from the extracorporeal treatment of blood in the dialyzer, and the second dialyzer port is an outlet port for the spent dialysis fluid.

31:

• The device of claim 1, wherein the processor circuitry is further configured to generate control signals for the pumping device, the adjustment arrangement, and a further pumping device.

32:

• The device of claim 1, wherein the ultrafiltration parameter is further determined based on fluid flow data representing fluid flow generated in the level adjustment period by one or more other pumping devices in direct or indirect fluid communication with blood in an extracorporeal blood circuit connected to the dialyzer.