A system for determining a position of a medical device in a respiratory system of a patient is provided. The system includes a positioning apparatus, a flexible guide rod having a distal portion, the flexible guide rod configured to be inserted into a passage of the respiratory system of the patient through the positioning apparatus, and an emitter coupled to the distal portion of the flexible guide rod. The system also includes a flexible guide tube, covering the flexible guide rod, and configured to move together with the guide rod through the positioning apparatus and the respiratory system of the patient, wherein the guide rod can be removed through the guide tube and positioning apparatus, leaving a passage into the respiratory system of the patient through the guide tube, a magnet external to the patient, the magnet configured to create a magnetic field in the patient, and at least three sensors positioned external to the patient, the at least three sensors configured to interact with the emitter positioned on the distal portion of the guide rod and the magnetic field created in the patient by the magnet. The system also includes a display screen and a computer connected to the display screen and the at least three sensors external to the patient, wherein the position of the emitter at the distal portion of the guide rod, relative to the respiratory system of the patient, is configured to be detected by at least one of the at least three sensors external to the patient, output to the computer, and indicated on the display screen in a schematic representation of the respiratory system of the patient.
