US 2025/0082833 A1Published application

Measurement of recirculation by means of two interim switches having kinetically different diffusion states

OwnerWaldemar Janikinventor

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Abstract

A blood treatment machine, module device and recirculation determination method feature a dialyser. A sensor is connected downstream of the dialyser and connected to a control unit that determines recirculation without blood-side bolus administration. The control unit: acquires the signal of a variable of consumed dialysis liquid measured by the sensor; switches the machine from a base mode into an interim mode, in which a dialysis liquid amount is confined in the dialyser on the dialysis liquid membrane side while blood flows in the blood circuit; changes into the base mode to supply the previously confined dialysis liquid amount as a first or second dialysis liquid bolus to the sensor to measure a signal change relative to a base signal as a corresponding first or second bolus signal; and deduces a recirculation from a deviation of the second bolus signal compared to the first bolus signal.

Claims15

Dependent claims

An extracorporeal blood treatment machine comprising:

a dialyser;
a control and computing unit;
and
at least one sensor device connected on a dialysis liquid-side downstream of the dialyser and electrically connected to the control and computing unit,
the control and computing unit being configured for determination of a presence of a recirculation without blood-side bolus administration and further configured:
to acquire at least one signal of a physical and/or chemical variable of a consumed dialysis liquid over time, being measured by the at least one sensor device for quantitative determination of at least one blood component in the consumed dialysis liquid,
to operate the extracorporeal blood treatment machine in a base mode for continuous operation in which the dialysis liquid flow through the dialyser is admitted,
to measure the at least one signal corresponding to the consumed dialysis liquid in the base mode as a base signal;
to switch the extracorporeal blood treatment machine from the base mode into an interim mode for interim operation, in which a dialysis liquid amount is confined in the dialyser on a dialysis liquid membrane side, while blood flow in a extracorporeal blood circuit is operated at a set blood flow rate, whereby blood on the blood membrane side continues to flow, for a respective duration of a pre-determined and/or predeterminable interim time interval;
to change into the base mode, in order to supply a previously confined dialysis liquid amount as a dialysis liquid bolus to the at least one sensor device, in order to measure a signal change, corresponding to the dialysis liquid bolus, relative to the base signal as a bolus signal;
and
to switch to the interim mode for a first interim time interval for establishment of equilibrium of the mass transfer, whereby a first dialysis liquid amount in the dialyser is confined at least until a concentration equilibrium of the at least one blood component is established on the dialysis liquid membrane side and the blood membrane side of the dialyser, which equilibrium is no longer changing or is only still changing to an unsubstantial degree,
the control and computing unit is, for forming a measurement cycle, further configured:
to switch to the interim mode for a second interim time interval shorter than the first interim time interval, whereby a second dialysis liquid amount in the dialyser is confined only as long as the concentration equilibrium of the blood component is not yet established, and
to deduce a presence of the recirculation from a deviation of a second bolus signal as a result of the second interim time interval compared to a first bolus signal as a result of the first interim time interval.

12 more elements

A module device for a determination of a recirculation for retrofitting an extracorporeal blood treatment machine with a dialyser, the module device comprising:

a control and computing unit which is configured as an electronics and evaluation unit operating independently of the extracorporeal blood treatment machine;
and
a sensor unit, electrically connected to the control and computing unit, with:
at least one sensor device;
and
a connecting section or part,
wherein the control and computing unit is configured to determine a presence of a recirculation without blood-side bolus administration, and is further configured:
to acquire the at least one signal, being measured by the at least one sensor device,
to operate the extracorporeal blood treatment in a base mode for continuous operation in which the dialysis liquid flow through the dialyser is admitted,
to measure the signal corresponding to the dialysis liquid consumed in the base mode as a base signal,
to switch the extracorporeal blood treatment from the base mode into an interim mode for interim operation, in which a dialysis liquid amount is confined in the dialyser on the dialysis liquid membrane side, while the blood flow in the extracorporeal blood circuit is operated at a set blood flow rate, whereby the blood on the blood membrane side continues to flow, for the respective duration of a pre-determined and/or predeterminable interim time interval,
to change into the base mode, in order to supply the previously confined dialysis liquid amount as a respective dialysis liquid bolus to the at least one sensor device, in order to measure a signal change, corresponding to the dialysis liquid bolus, relative to the base signal as a corresponding bolus signal,
to switch to the interim mode for a first interim time interval for establishment of equilibrium of the mass transfer, whereby a first dialysis liquid amount in the dialyser is confined at least until a concentration equilibrium of the blood component is established on the dialysis liquid membrane side and the blood membrane side of the dialyser, which equilibrium is no longer changing or is only still changing to an unsubstantial degree, and
wherein:
the control and computing unit is, for forming a measurement cycle, further provided and configured:
to switch to the interim mode for a second interim time interval shorter than the first interim time interval, whereby a second dialysis liquid amount in the dialyser is confined only as long as the concentration equilibrium of the blood component is not yet established,
to deduce, from a deviation of a second bolus signal as result of the second interim time interval compared to a first bolus signal as result of the first interim time interval, the presence of the recirculation.

14 more elements

A method for monitoring a recirculation in an extracorporeal blood treatment comprising the steps of:

predetermining a first interim time interval within which a concentration equilibrium of a blood component is established;
predetermining a second interim time interval, which is shorter than the first interim time interval, within which the concentration equilibrium of the blood component is not yet established;
deducing a first bolus signal as result of the first interim time interval comprising the following substeps:
operating an extracorporeal blood treatment machine in a base mode while measuring the signal corresponding to the consumed dialysis liquid as a base signal;
switching over from the base mode into an interim mode, for a duration of the first interim time interval;
changing back into the base mode to supply the previously confined dialysis liquid amount as the first dialysis liquid bolus to the at least one sensor device, and subsequently measuring the first bolus signal as a signal change, corresponding to the first dialysis liquid bolus, relative to the base signal;
deducing a second bolus signal as result of a second interim time interval, before or after the step of deducing of the first bolus signal, the step of deducing the second bolus signal comprising the following substeps:
operating the extracorporeal blood treatment machine in the base mode;
measuring the signal corresponding to the dialysis liquid consumed in the base mode as a base signal;
switching over from the base mode into the interim mode for the duration of the second interim time interval;
changing back into the base mode to supply the previously confined dialysis liquid amount as the second dialysis liquid bolus to the at least one sensor device, and subsequently measuring of the second bolus signal as a signal change, corresponding to the second dialysis liquid bolus, relative to the base signal;
and
deducing the presence of the recirculation from a deviation of the second bolus signal compared to the first bolus signal.

10 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/572,414Filed 24 Jun 2022
Priority: DE 10 2021 116 343.924 Jun 2021
Published: 13 Mar 2025
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

A61M 1/1609
Physical characteristics of the dialysate fluid: after use, i.e. downstream of dialyser
A61M 1/3621
Other treatment of blood in a by-pass of the natural circulatory system, e.g. temperature adaptation, irradiation ; Extra-corporeal blood…
A61M 1/1617
Control or regulation: using measurements made during a temporary variation of a characteristic of the fresh dialysis fluid
A61M 1/165
Constructional aspects thereof: with a dialyser bypass on the dialysis fluid line