Bronchial blocker
An bronchial blocker ( also called endobronchial blocker ) is a device which can be inserted down a tracheal tube after tracheal intubation so as to block off the right or left main bronchus of the lungs in order to be able to achieve a controlled one sided ventilation of the lungs in thoracic surgery . 
<triplet> tracheal tube <subj> tracheal intubation <obj> use