An infusion system is controlled by driving a displacing element (3) in alternate fill and pump directions in a fluid chamber (8) to define a varying displacement volume, and by synchronously operating a valve arrangement (6, 7) to alternately open and close first and second fluid paths (4, 2) from the fluid chamber (8) to a source (5) and a connector (19a), respectively, such that an infusion liquid is repeatedly sucked into the fluid chamber (8) from the source (5) and pumped from the fluid chamber (8) through the connector (19a). The infusion system comprises a sensor (12) for generating a measurement signal representative of fluid pressure in the displacement volume. A controller (11) is connected to intermittently effect a system test, in which the valve arrangement (6, 7) is operated to close the second fluid path (2) the displacing element (3) is driven a given distance in the fill direction and the measurement signal is obtained from the sensor (12) during at least part of the system test. The integrity of the infusion system is determined based on the measurement signal, e.g. by evaluating the temporal change in the measurement signal during and/or after the displacement. The system test may identify a shortage of infusion liquid in the source (5) or a leakage of air into the first fluid path (4).La présente invention concerne un système de perfusion qui est commandé en entraînant un élément de déplacement (3) dans des directions de remplissage et de pompage alternées dans une chambre de fluide (8) pour définir un volume de déplacement variable, et en actionnant de façon synchrone un agencement de vanne (6, 7) pour ouvrir et fermer de façon alternée des premier et deuxième chemins de fluide (4, 2) provenant de la chambre de fluide (8) vers une source (5) et un connecteur (19a), respectivement, de sorte quun liquide de perfusion soit aspiré de façon répétée dans la chambre de fluide (8) depuis la source (5) et pompé depuis la chambre de fluide (8) par linter
