Transfusion apparatus

Transfusion apparatus comprising:

• a finger-type peristaltic pump including (1) a resilient, longitudinal transfusion tube containing liquid to be fed by the transfusion apparatus, (2) a plurality of finger elements disposed in a series along the longitudinal axis of said transfusion tube, and (3) drive means for momentarily actuating said finger elements one after another in a recurrent succession so that the actuated finger elements press on and occlude said transfusion tube and cause the liquid in said tube to move longitudinally along the tube ahead of the actuated finger elements;
• means responsive to said peristaltic pump for producing a reference position indicating output signal each time the finger elements of said pump reach a predetermined reference point in said recurrent succession, and for producing a succession of working position indicating output signals each indicating that said recurrent succession has progressed a predetermined increment beyond said reference point;
• and
• drive control means responsive to said reference and working position indicating output signals for determining the rate at which said finger elements must be actuated at the point in said recurrent succession at which said reference and working position indicating signals indicate that the pump currently is in order to maintain a constant liquid delivery amount of the pump and for causing said drive means to actuate said finger element at that rate.