Infusion pump with phase separator

An infusion pump comprising a substance and pushing fluid inlet, a substance outlet, a central chamber communicating with said inlet and said outlet, and injecting means for injecting a substance into a biological object, wherein the infusion pump further includes a pushing fluid outlet in communication with the central chamber in such a way as to allow a pushing fluid to exhaust the pump. The outlet of the infusion pump is advantageously connected to the proximal end of a catheter, the distal end being inserted into the biological object. A sensor, e.g., an optical device, is preferably placed at the outlet of the infusion pump and checks that the outlet is free of gas. The infusion pump is preferably remotely controlled so that it can be placed in limited access locations. It is also preferably computer controlled.