Device for an extracorporeal blood treatment, and method for determining a hemodynamic parameter during an extracorporeal blood treatment

A method for determining a hemodynamic parameter during an extracorporeal blood treatment, comprising:

• providing an extracorporeal blood treatment device comprising
• a blood treatment unit comprising at least one compartment, the a least one compartment comprising a first connection and a second connection,
• a first blood line connected to the first connection of the at least one compartment and comprising a first patient connection,
• a second blood line connected to the second connection of the at least one compartment and comprising a second patient connection,
• a blood pump, and
• a measuring apparatus for measuring a physical or chemical characteristic variable;
• and, wherein either
• for a first measurement cycle of two measurement cycles, the blood pump is operated in an operating mode comprising a reversed blood flow, such that blood flows from the second patient connection to the blood treatment unit and from the blood treatment unit to the first patient connection, and, for a second measurement cycle of the two measurement cycles, operating the blood pump in an operating mode comprising a normal blood flow, such that blood flows from the first patient connection to the blood treatment unit and from the blood treatment unit to the second patient connection, and a hemodynamic parameter is determined from a measured physical or chemical characteristic variable in the two measurement cycles when the blood flow is normal and when the blood flow is reversed, or,
• for the first measurement cycle, the blood pump is operated in an operating mode comprising a reversed blood flow, such that blood flows from the second patient connection to the blood treatment unit and from the blood treatment unit to the first patient connection, and the hemodynamic parameter is determined from the measured physical or chemical characteristic variable in the first measurement cycle when the blood flow is reversed,
• and further wherein the operation of the blood pump in the operating mode comprising a reversed blood flow is only enabled during a specified time interval.

A device for extracorporeal blood treatment, comprising:

• a blood treatment unit comprising at least one compartment, the at least one compartment comprising a first connection and a second connection;
• a first blood line connected to the first connection of the at least one compartment, the first blood line comprising a first patient connection;
• a second blood line connected to the second connection of the at least one compartment, the second blood line comprising a second patient connection;
• a blood pump;
• a measuring apparatus configured to measure a physical or chemical characteristic variable;
• an input unit configured to receive an input comprising a time interval;
• and
• a control and evaluation unit connected to the blood pump and to the measuring apparatus and configured to carry out a measurement cycle, wherein
• for the measurement cycle, the blood pump is operated in an operating mode comprising a reversed blood flow, such that blood flows from the second patient connection to the blood treatment unit and from the blood treatment unit to the first patient connection, and a hemodynamic parameter is determined from a measured physical or chemical characteristic variable measured during the measurement cycle,
• and further wherein
• the control and evaluation unit is further configured such that the operation of the blood pump in the operating mode comprising the reversed blood flow is only enabled during the time interval received by the input unit.