A device and method for verifying the proper position of catheters in the body by means of acoustic reflectometry, the device including a sound source, one or more sound receivers, a tube with compliant walls and open distal end to be introduced through an entrance to a body cavity, the sound source and receiver(s) coupled to the proximal end of the tube, a processor for causing the sound source to generate an acoustic excitation signal, the processor processing the acoustic signals sensed by the sound receiver(s) and generating an approximation of the acoustic impulse response of the tube, and the processor analyzing the acoustic impulse response to determine the position of the tube in the body cavity.