Apparatus and method for influencing and/or detecting magnetic particles comprising bridge unit

摘要

The present invention relates to an apparatus and a method for influencing and/or detecting magnetic particles in a field of view (28). The apparatus comprises selection means for generating a magnetic selection field (50) and drive and receiving means comprising one or more combined drive field and selection coils (441) for changing the position in space of the two sub-zones (52, 54) in the field of view (28) and for acquiring detection signals. A balanced bridge unit (160) comprising inductive or capacitive coupling elements (411, 421) is provided between the drive field signal generator unit (122) and the signal receiving unit (140) as a light-weight, inexpensive and easily implementable solution for reducing the harmonic background.

主权项

1. An apparatus for influencing and/or detecting magnetic particles in a field of view, wherein the apparatus comprises:
a selection field signal generator unit and selection field elements for generating a magnetic selection field having a pattern in space of its magnetic field strength such that a first sub-zone having a low magnetic field strength where a magnetization of the magnetic particles is not saturated and a second sub-zone having a higher magnetic field strength where the magnetization of the magnetic particles is saturated are formed in the field of view, a drive field signal generator unit, a signal receiving unit and a drive-receiving coil, said drive-receiving coil being configured both for changing a position in space of the first and second sub-zones in the field of view by a magnetic drive field so that the magnetization of the magnetic particles changes locally and for acquiring detection signals, wherein the detection signals depend on the magnetization of the magnetic particles in the field of view, wherein the magnetization is influenced by the change in the position in space of the first and second sub-zones, a bridge unit coupled between said drive field signal generator unit and said signal receiving unit, said bridge unit comprising
a first bridge sub-unit comprising a first inductive or capacitive coupling element,a second bridge sub-unit comprising a second inductive or capacitive coupling element,a third bridge sub-unit coupled in series with said first bridge sub-unit, said third bridge sub-unit comprising a measurement inductor, anda fourth bridge sub-unit coupled in series with said second bridge sub-unit, said fourth bridge sub-unit comprising said drive-receiving coil, anda coupling unit coupled between the drive field signal generator unit and the bridge unit for coupling into the bridge unit, wherein the signal receiving unit is coupled to a first output terminal arranged between the first and second bridge sub-units and a second output terminal arranged between the third and fourth bridge sub-units.