Apparatus for extracorporeal treatment of blood and method for determining a parameter indicative of the progress of an extracorporeal blood treatment

An apparatus for an extracorporeal treatment of blood comprising:

• a blood treatment unit having a primary chamber and a secondary chamber separated by a semi-permeable membrane;
• a preparation line having one end connected to an inlet of the secondary chamber of the blood treatment unit and configured to convey fresh treatment liquid to the secondary chamber, the fresh treatment liquid presenting a characteristic selected from a group consisting of:
• a conductivity in the fresh treatment liquid, and
• a concentration of at least one substance in the fresh treatment liquid;
• a spent dialysate line having one end connected to an outlet of said secondary chamber and configured to remove spent liquid from the secondary chamber, the spent liquid presenting a characteristic selected from a group consisting of:
• a conductivity in the spent liquid, and
• a concentration of at least one substance in the spent liquid;
• and
• a control unit configured to command execution of a task for determining a parameter indicative of an effectiveness of the extracorporeal treatment of blood, said task comprising the following steps:
• receiving at least one prescription baseline for the characteristic in the fresh treatment liquid,
• receiving a flow rate, or a parameter correlated to the flow rate, of the fresh treatment liquid in the preparation line,
• causing the fresh treatment liquid to flow in the preparation line to the secondary chamber with the characteristic being at said at least one prescription baseline,
• causing the spent liquid to flow out of the secondary chamber into the spent dialysate line,
• computing an amplitude and a duration over time of an upstream variation as a function of the flow rate or the parameter correlated to the flow rate,
• causing the upstream variation, by implementing the computed amplitude and the duration over time, of a value of the characteristic in the fresh treatment liquid with respect to said at least one prescription baseline, thereby causing a corresponding and timely delayed downstream variation of the same characteristic in the spent liquid flowing in the spent dialysate line, and
• computing at least one value of a parameter indicative of the effectiveness of the extracorporeal treatment of blood by using values correlated to the upstream variation of the value of the characteristic in the fresh treatment liquid and values correlated to the downstream variation of the same characteristic in the spent liquid,
• wherein computing either or both the amplitude and the duration over time comprises selecting either or both the amplitude and the duration over time among a plurality of fixed amplitudes and/or fixed durations over time stored in the control unit and each corresponding to a range which the received flow rate falls in, wherein said range is one of a plurality of ranges of flow rates stored in the control unit.

An apparatus for an extracorporeal treatment of blood comprising:

• a blood treatment unit having a primary chamber and a secondary chamber separated by a semi-permeable membrane;
• a preparation line having one end connected to an inlet of the secondary chamber of the blood treatment unit and configured to convey fresh treatment liquid to the secondary chamber, the fresh treatment liquid presenting a characteristic selected from a group consisting of:
• a conductivity in the fresh treatment liquid, and
• a concentration of at least one substance in the fresh treatment liquid;
• a spent dialysate line having one end connected to an outlet of said secondary chamber and configured to remove spent liquid from the secondary chamber, the spent liquid presenting a characteristic selected from a group consisting of:
• a conductivity in the spent liquid, and
• a concentration of at least one substance in the spent liquid;
• and
• a control unit configured to command execution of a task for determining a parameter indicative of an effectiveness of the extracorporeal treatment of blood, said task comprising the following steps:
• receiving at least one prescription baseline for the characteristic in the fresh treatment liquid,
• receiving a flow rate, or a parameter correlated to the flow rate, of the fresh treatment liquid in the preparation line,
• causing the fresh treatment liquid to flow in the preparation line to the secondary chamber with the characteristic being at said at least one prescription baseline,
• causing the spent liquid to flow out of the secondary chamber into the spent dialysate line,
• computing an amplitude and a duration over time of an upstream variation as a function of the flow rate or the parameter correlated to the flow rate,
• causing the upstream variation, by implementing the computed amplitude and the duration over time, of a value of the characteristic in the fresh treatment liquid with respect to said at least one prescription baseline, thereby causing a corresponding and timely delayed downstream variation of the same characteristic in the spent liquid flowing in the spent dialysate line, and
• computing at least one value of a parameter, indicative of the effectiveness of the extracorporeal treatment of blood, by using values correlated to the upstream variation of the value of the characteristic in the fresh treatment liquid and values correlated to the downstream variation of the same characteristic in the spent liquid,
• wherein the task comprises causing the upstream variation of the value of the characteristic such that the upstream variation of the value of the characteristic is all above or all below the at least one prescription baseline, and wherein said amplitude is a difference between the at least one prescription baseline and a maximum or a minimum of the upstream variation.