An exhaust gas flow control system for an oxygenator 20 of an extracorporeal ventilation system connected to an oxygenation gas supply line 24 and an exhaust line 26 for removal of an exhaust gas, where the exhaust gas flow system comprises an exhaust gas pressure regulator 268 thats responsive to a controller to maintain a pre-determined pressure level in the exhaust line 26. The exhaust gas pressure regulator 268 may maintain a sub-atmospheric pressure in the exhaust line 26. The exhaust gas flow control system may further comprise: an exhaust flow regulator 264 responsive to the controller, which maintains a pre-determined flow rate of the exhaust gas passing through the exhaust flow regulator 264 a flow control path 262 controlled by the exhaust flow regulator 264 and a pressure control path 266 controlled by the exhaust gas pressure regulator 268 a supply line pressure regulator 38 upstream of the oxygenator 20. The exhaust gas flow control system may be configured to maintain the flow rate through the flow control path 262 at the pre-determined exhaust gas flow rate. Described as providing a better degree of control over the pressure across an oxygenators gas inlet and its exhaust.
