Abstract: Methods for the adjustment of a blood flow in a blood treatment machine/dialysis machine are disclosed. Steps for achieving a blood flow having an optimum value include determining a blood flow target value, altering the blood flow at a predetermined blood flow alteration rate, comparing a venous pressure with a venous pressure threshold, an arterial pressure with an arterial pressure threshold, and the blood flow with the blood flow target value, determining if a dialysis fluid parameter extreme is reached, storing an optimum blood flow value, in dependence on a blood flow (according to a value which is stored in a data table and which takes into account the blood flow target value as well as the measurement lag) in an optimum blood flow value memory, for which the dialysis fluid parameter threshold, the venous pressure threshold or the arterial pressure threshold, or the blood flow target value has been reached.

Abstract: Control methods of a dialysis machine for allowing the dialysate-side detection of a recirculation in an arteriovenous shunt of a patient during ongoing hemodialysis are described. A sensor is arranged downstream of a dialyser and detects a change of a physicochemical parameter PD of outflowing dialysis fluid. Control elements are provided to guide the dialysis fluid in a selected manner through the dialyser or pass it by.