A tracheal tube having a distal end for placement in a patient's trachea. In one embodiment, the tracheal tube includes a preformed curved proximal end that directs the tracheal tube, upon leaving the patient's mouth, toward the patient's left or right ear depending on the particular preformed curvature....http://www.google.es/patents/US5333608?utm_source=gb-gplus-sharePatente US5333608 - Endotracheal tube for face, chin and neck surgery
