| 摘要 |
<p>An_apparatus for magnetic induction tomography comprising at least one transmitter coil (LTX) for the introduction of an alternating magnetic field into a target body (OBJ) to be investigated, at least one receiver coil (LRX) for the pick-up of received signals and means for processing the received signals which reconstructs an image of the spatial electrical properties in the object from the amplitudes and phases of the received signals, the at least one transmitter coil being driven by a power amplifier (PA) having a low output impedance and working at two or more different frequencies (f L , f H ), whereby two or more feeding paths (Pf L , Pf H ) for the two or more frequencies (f L , f H ) are provided for each transmitter coil (L TX ), in each feeding path the transmitter coil being driven at the corresponding frequency (f L , f H ), via a »/4-transformer (Tf L , Tf H ), said coil being in series resonance with a series capacitor (C L , C H ) of said path at said one frequency, whereas the other feeding path(s) showing essentially high impedance for said one frequency.</p> |
