Patent ID: 7096148

Claim:
An electromagnetic tracking system comprising: a magnetic field generating unit having at least one field generating coil driven by a drive signal, a field sensing unit having at least one field sensing coil generating a sensing signal responsive to a changing magnetic field, said changing magnetic field including a position-dependent field produced by said magnetic field generating unit, the generating and sensing units being arranged to generate and to sense, respectively, an electromagnetic field in an arena of interest, and wherein at least one of said units is movable, signal measurement and conditioning circuitry connected to said units to (i) synchronously sample and digitize drive signal data and sensing signal data for respective pairs of field generating and field sensing coils, cumulating the digitized data to form a raw signal matrix, and (ii) determine a mutual inductance matrix from the raw signal matrix, and a processor that utilizes the mutual inductance matrix to determine coordinates of the movable unit.