Patent ID: 7393337

Claim:
A method of monitoring the operationality of a member for cutting off the flow of a fluid through an extracorporeal circuit, said circuit having at least one length of deformable tubing on which there is at least one active flow cut-off member having at least one movable portion that can be actuated between an open condition, allowing the fluid to pass through said length of deformable tubing, and at least one closed condition, preventing the fluid from passing through said length of deformable tubing, said method comprising the following steps: moving the movable portion of the cut-off member from said open condition towards said closed condition; associating at least one dynamic parameter with a motion of said movable portion, said at least one dynamic parameter relating to a condition of motion of said movable portion, said at least one dynamic parameter being selected from: p1, corresponding to a time interval dT taken by the movable portion to move between a first predetermined position and a second predetermined position, at a distance from said first predetermined position, p2, corresponding to a speed of said movable portion at a first predetermined position, p3, corresponding to an acceleration of said movable part at a first predetermined position, p4, corresponding to a function F(p1) of said parameter p1, p5, corresponding to a function F(p2) of said parameter p2, p6, corresponding to a function F(p3) of said parameter p3, and p7, corresponding to a function of two or more of said parameters p1, p2, p3; determining a value of said at least one dynamic parameter relating to said movable portion at least during said movement; and checking that the value assumed by said at least one dynamic parameter satisfies a predetermined criterion of acceptability.