METHOD FOR DETERMINING THE PERCENTAGE OF RECIRCULATION IN A FISTULA AND/OR CARDIOPULMONARY RECIRCULATION RELATIVE TO THE TOTAL FISTULA RECIRCULATION AND CARDIOPULMONARY RECIRCULATION

摘要

The method according to the invention and the apparatus according to the invention are characterized in that the substitution rate Q_s is modified by a predefined amount upstream or downstream of the dialyzer or filter while the flow rate Q_FM of the liquid withdrawn through the dialyzer membrane is modified. The blood volume RBV(t) or a variable correlated with the blood volume, e.g. the hematocrit Hct(t), is determined before and after modifying the substitution rate or the flow rate of the liquid withdrawn through the dialyzer or filter membrane in order to calculate fistula recirculation R_A. In addition, the total recirculation R is determined. The percentage of fistula recirculation (R_A) and/or cardiopulmonary recirculation (R_CP) relative to the total recirculation is calculated from the determined fistula recirculation (R_A) and the sum R of fistula recirculation (R_A) and cardiopulmonary recirculation (R_CP).