According to various embodiments, a sensor may be placed on a patient chest adjacent to a desired position of a distal end of a tracheal tube. The sensor may be configured to emit an electromagnetic field into the patient and detect perturbations to that field caused by the presence of the tracheal tube. As the tube is inserted within the trachea, the sensor may detect the tube when the distal end passes within range of the sensor, indicating that a proper insertion depth has been reached. In certain embodiments, multiple sensors may be placed along the chest adjacent to the trachea to determine a distance between the tube and an anatomical structure. The distance information may provide an indication as to whether the tracheal tube is properly placed within the trachea.