Patent ID: 8903482

Claim:
An apparatus ( 100 ) for non-invasive intracardiac electrocardiography (ECG) by use of a magnetic and electrically conducting interference device ( 210 ), which apparatus comprises: ECG means ( 151 , 230 ) for recording ECG signals, selection means comprising a selection field signal generator unit ( 110 ) and selection field elements ( 116 ), in particular selection field magnets or coils, for generating a magnetic selection field ( 50 ) having a pattern in space of its magnetic field strength such that a first sub-zone ( 52 ) having a low magnetic field strength and a second sub-zone ( 54 ) having a higher magnetic field strength are formed in a field of view ( 28 ), drive means comprising a drive field signal generator unit ( 130 ) and drive field coils ( 136 a , 136 b , 136 c ) for changing the position in space of the two sub-zones ( 52 , 54 ) in the field of view ( 28 ) by means of a magnetic drive field so that the magnetization of the interference device ( 210 ) in the field of view ( 28 ) changes locally, receiving means comprising at least one signal receiving unit ( 140 ) and at least one receiving coil ( 148 ) for acquiring detection signals, which detection signals depend on the magnetization of the interference device ( 210 ) in the field of view ( 28 ), which magnetization is influenced by the change in the position in space of the first and second sub-zone ( 52 , 54 ), control means ( 150 ) for controlling said signal generator units ( 110 , 130 ) to generate and provide control currents to the respective field coils to generate appropriate magnetic fields for moving the interference device through the vessel system and the heart in a direction instructed by movement commands and/or for holding the interference device ( 210 ) at a constant position, processing means ( 154 ) for processing said detection signals acquired when appropriate magnetic fields are applied for determining the position of the interference device ( 210 ) within the vessel system and the heart from the processed detection signals, and evaluation means ( 153 ) for evaluating the influence of the interference device on the ECG signals recorded by the ECG means ( 151 , 230 ).