An extracorporeal dialysis circuit (1) of a dialysis machine comprising at least one dialysis filter (2), an arterial line (3), which is responsible for the transport of the blood from a patient (P) to the filter (2), a venous line (4), which is responsible for the transport of the blood from the filter (2) to the patient (P), at least one infusion assembly (7, 8) comprising a syringe (10) and an infusion line (7a, 8a) adapted to transport the substance injected respectively by the syringe (10) to one of the liquids involved in the dialysis treatment. The infusion assembly (7, 8) comprises a pressure sensor (11), which is directly connected to an outlet portion of the syringe (10).
