Patent ID: 8641656

Claim:
A calculation and control system for the determination of the state of a vascular access of a patient intended to follow successive sessions (i,j) of extracorporeal blood treatment by extraction and return of the blood via the vascular access, each successive extracorporeal blood treatment session comprising circulating the blood of the patient, at an extracorporeal blood flow rate, in an extracorporeal blood circuit having an extracorporeal arterial line, a filter and an extracorporeal venous line, the system comprising the following means: a) means for determining a value (P 1 i, P 1 j, P 2 i, P 2 j, . . . ) of at least one hemodynamic extracorporeal parameter (P 1 , P 2 . . . ) of the patient for at least two sessions (i,j), b) means for determining a value (Ei, Ej) of purification effectiveness of the extracorporeal blood treatment for at least two sessions (i,j), wherein the purification effectiveness is equal or a function of at least one in the group of: the dialysance (D), the clearance (C), the concentration of a substance contained in the blood before the filter (Cbin), the concentration of a substance contained in the blood after the filter (Cbout) in the extracorporeal circuit, the dialysis dose (KT/v) under conditions of equal session durations, c) programmed means for determining a risk score relating to the state of the vascular access of the patient as a function of at least two values (Pi, Pj) of the hemodynamic extracorporeal parameter and of at least two determined values (Ei, Ej) of the purification effectiveness.