An improved insufflation-exsufflation system for removal of broncho-pulmonary secretions with automatic triggering of inhalation phase includes a conduit for connection to a patients airway a pressure source with a positive pressure port and a negative pressure port a switching device selectively connecting the conduit to the positive pressure port, the negative pressure port and the dwell port the sensor system for sensing an inhalation by the patient and a controller system for driving the switching device to connect the conduits sequentially to the positive port, the negative port and the dwell port and to return again to the positive port in response to the sensor system sensing an inhalation by the patient while the conduit is connected to the dwell port.
