Methods and apparatuses for locating a catheter, or other medical international devices are described herein. In one aspect of the invention, an exemplary method includes providing a pressure sensitive device attached to a body of a catheter, providing a resonant circuit coupled to the pressure sensitive device in the catheter, the resonant circuit having an oscillating frequency, generating a magnetic field, the magnetic field inducing and causing the resonant circuit to oscillate, applying a pressure on the pressure sensitive device, the pressure applied on the pressure sensitive device changing the frequency of the resonant circuit, detecting the oscillation of the resonant circuit, and determining location of the catheter based on the oscillation of the resonant circuit. Other methods and apparatuses are also described.