Patent ID: 7976533

Claim:
A method for operating an apparatus for removing body fluids from a body cavity by suction, the apparatus comprising: a catheter having a drainage lumen and an auxiliary lumen adapted for placement adjacent a wound in the body cavity to be drained of body fluid, the drainage lumen having a proximal end being in fluid communication with a proximal end of the auxiliary lumen; a container for connection in fluid communication with the drainage lumen and for receiving body drainage fluid from the body cavity; a source of suction for effecting negative pressure in the drainage lumen and a valve for opening the auxiliary lumen in order to supply air or gas to the body cavity; the method comprising the steps of measuring the pressure in the auxiliary lumen, opening the auxiliary lumen; and increasing the pressure difference between a pressure in the drainage lumen and a pressure in the atmosphere only when the pressure measured in the auxiliary lumen corresponds at least to atmospheric pressure, wherein the pressure difference is increased by increasing the power of the source of suction.