Technology has played a large part in the development of modern medical ventilators. However, the introduction of a multitude of new modes has not been accompanied by good quality outcomes research. Dual modes, combining pressure limitation with guaranteed tidal volume, have been developed. Physicians are now demanding more control over gas flow than before - hence the development of active exhalation valves, dynamic inspiration valves, rise time control, automatic tube compensation and, of course, waveform analysis. Modern medical ventilators deliver enhanced patient interactivity using better triggering sensors, and more comfortable spontaneous breathing - even in inverse ratio ventilation. AN exciting prospect is the gradual arrival of high frequency oscillation into adult critical care units. Using this technique, the physician sets the mean airway pressure, and there is minimal tidal gas movement.