Patent ID: 8874188

Claim:
An arrangement for at least one of influencing and detecting magnetic particles in a region of action, wherein the arrangement comprises: a selector configured to generate a magnetic selection field having a pattern in space of a magnetic field strength such that a first sub-zone having a low magnetic field strength and a second sub-zone having a higher magnetic field strength are formed in the region of action; a driver configured to change a position in space of the two sub-zones in the region of action by a magnetic drive field so that magnetization of the magnetic particles changes locally, said driver comprising drive field coil units; a receiver configured to acquire detection signals, wherein the detection signals depend on the magnetization in the region of action, wherein the magnetization is influenced by a change in the position in space of the two sub-zones, drive field generator units for generating drive signals for said drive field coil units; drive signal amplifiers configured to amplify said drive signals; a coupler coupled between said drive signal amplifiers and said drive field coil units, said coupler comprising at least one tank circuit coupled to an output of said drive field amplifiers and a reactive coupling unit coupled between an output of said at least one tank circuit and an input of the respective drive field coil unit, wherein said at least one tank circuit comprises a capacitor and an inductor connected in parallel and at least one switched reactive element; at least one switch connected in series with the at least one switched reactive element to form a series connection, and configured to connect and disconnect the at least one switched reactive element from the parallel connected capacitor and the inductor, wherein the parallel connected capacitor and inductor are further connected in parallel with the series connection of the at least one switch and the at leapt one switched reactive element; and a controller configured to operate said at least one tank circuit at a variable operating frequency by opening and closing the at least one switch to connect and disconnect the at least one switched reactive element from the parallel connected capacitor and the inductor.