Patent ID: 7172570

Claim:
An apparatus for monitoring a vascular access associated with an extracorporeal blood circuit, comprising: at least a first pump predisposed for circulation of a fluid in at least one of the extracorporeal blood circuit and at least one fluid transport line cooperating with the extracorporeal blood circuit; at least a second pump predisposed for circulation of a fluid in another of either the extracorporeal blood circuit or the fluid transport line cooperating with the extracorporeal blood circuit; a memory, containing a mathematical model of the vascular access comprising: at least a first parameter relating to at least one characteristic (R d , R f , R v , q a , q f , q v ) at least a second parameter relating to at least one characteristic (P) of the blood; and at least a third parameter relating to a flow rate (q b , q u ) of the fluid moved by the first pump; at least a fourth parameter relative to the flow rate (q b , q uf ) of the fluid made to circulate in the second pump; a control and calculation unit connected to the memory and to the first pump and programmed to perform a monitoring procedure which comprises the following operating stages: varying the flow rate of the first pump; receiving the signals corresponding to the values (P af , P am , P vf , P vm ) assumed by the characteristic (P) of the blood in at least one zone of the blood circulation path and with at least two different values of the flow rate (q b , q uf ) of the first pump; storing in memory the values of the characteristic of the blood and the corresponding values of the flow rate of the first pump; and processing the values stored in memory by means of the mathematical model, in order to determine at least one value of a characteristic of the vascular access.