Patent ID: 8391953

Claim:
An invasive medical apparatus, comprising: A catheter, having a distal end, configured to be inserted into a heart of a subject, the catheter comprising a wireless position sensor fixed adjacent to the distal end of the catheter to wirelessly transmit position signals indicative of a position of the catheter within the heart, the wireless position sensor comprising a power coil, a power circuit, and a sensing coil, where the power coil is configured to be driven inductively by a radio-frequency (RF) electromagnetic field to provide operating energy to the wireless position sensor; A signal processing unit external to the subject for determining position and orientation coordinates of the wireless position sensor based on the position signals transmitted by the power coil of the wireless position sensor; A power transmitter configured to generate the RF electromagnetic field in a vicinity of the subject, and dependent upon the spatial position and orientation of the sensing coil, cause currents to flow in the sensing coil, where the power circuit converts the currents into position signals which are transmitted by the power coil to the signal processing unit; A passive energy transfer amplifier configured to be placed on a part of the subject near the heart to enhance inductive driving of the power coil of the wireless position sensor, by amplifying the RF electromagnetic field and causing a greater current flow in the power coil of the wireless position sensor.