Described embodiments include an apparatus, which includes a catheter configured for insertion into a body of a subject, the catheter comprising a flexible distal portion configured to flex in response to a mechanical force applied to the catheter, a conducting element, held by the flexible distal portion of the catheter such that a position of the conducting element changes as the flexible distal portion flexes, at least one transmitting coil, disposed within the catheter proximally to the conducting element, configured to generate an alternating magnetic field that induces, in the conducting element, eddy currents that vary with the position of the conducting element, and one or more receiving coils, disposed within the catheter proximally to the conducting element, configured to output respective signals responsively to a superposition of (i) the magnetic field generated by the transmitting coil, and (ii) a secondary magnetic field generated by the eddy currents.
