A medical pump includes first and secondcompartments, which are configured to accept respectivefirst and second containers of fluid to be pumped to amedical device, and a paddle, which is fitted between thefirst and second compartments. The pump additionallyincludes a control module, which is configured to drivethe paddle to alternate between first time periods inwhich the paddle applies pressure to the first containerso as to pump the fluid therefrom, and second timeperiods in which the paddle applies the pressure to thesecond container so as to pump the fluid therefrom.
