Monitoring of the pressure of a product fluid to be administered in dosed amounts during infusion or injection

Apparatus for the monitoring of the pressure of a product fluid which is dispensable in dosed amounts for the purpose of an infusion or injection from a container (2) by advancement of a piston (6) received in the container (2), wherein the apparatus comprises:

• a) a housing (1) receiving the container (2) or forming the latter,
• b) a force sensor (13) which measures a reaction force serving as a measure of the pressure and exerted by the piston (6) onto the housing (1) and outputs it as a measured value, and
• c) a control (20) which compares the measured value with a predetermined reference value and controls a drive (7 to 11) for the piston (6) under consideration of the result of the comparison, characterized in that,
• d) at least one nominal value (S;
• S′) for the reaction force is stored in a memory (22, 23) of the control (20) and used for a direct nominal/actual comparison with the measured reaction force.

An apparatus for monitoring the pressure of a product fluid which is dispensable in dosed amounts for the purpose of an infusion or injection from a container by advancement of a piston received in the container, comprising:

• a) a housing;
• b) a force sensor which measures a reaction force which serves as a measure of the pressure exerted by the piston and outputs it as a measured value;
• and
• c) a controller which compares the measured value with a predetermined reference value and controls a drive for the piston under consideration of the result of the comparison, wherein at least one nominal value for the reaction force is stored in a memory of the controller and used for a direct nominal/actual comparison with the measured reaction force.