| abstract |
Determining the placement of an endotracheal tube in a patient. The invention evaluates discontinuities in the medium surrounding the endotracheal tube (10), such as airway (18), as a function of distance past an end of the endotracheal tube. Using a loudspeaker (32) to generate sound waves, the sound waves propagate through a coiled wavetube (64), a connecting adapter (30), and an endotracheal tube (10), into the are of interest. With a processing system (40), reflected sound waves which return from the cavity back to a microphone (38) within the wavetube are analyzed and an area-distance curve (44) of the area in interest is constructed. |