Patent ID: 8154276

Claim:
A method for locating at least one magnetic marker ( 100 ) in a region of action ( 300 ), wherein the method comprises the steps of generating a magnetic drive field ( 221 ) so that the magnetization of the magnetic marker ( 100 ) changes, generating a magnetic selection field ( 211 ) having a pattern in space of its magnetic field strength, acquiring a first signal ( 231 ′) by means of a first receiving probe ( 231 ) and acquiring a second signal ( 232 ′) by means of a second receiving probe ( 232 ), the first receiving probe ( 231 ) and the second receiving probe ( 232 ) being located at different locations relative to the region of action ( 300 ), the first signal ( 231 ′) and the second signal ( 232 ′) depending on the magnetization of the magnetic marker ( 100 ) in the drive field ( 221 ) and in the selection field ( 211 ) and further depending on the location of the magnetic marker ( 100 ), the magnetic selection field ( 211 ) having a first magnetic field strength configuration, repeating at least once the acquisition of the first signal ( 231 ′) and of the second signal ( 232 ′) in the presence of the selection field ( 211 ) having a second magnetic field strength configuration, computing an estimation of the location of the magnetic marker ( 100 ) by means of the acquired signals ( 231 ′, 232 ′).