In internal medicine, a simple method for the functional examination of the
gastrointestinal tract without the risk of radiation exposure is required.
We describe a novel principle based on the monitoring of magnetic markers w
hich meets these demands. Our method employs a special permanent magnet whi
ch is repeatedly aligned by a vertically oriented pulsed magnetic field. Du
e to this alignment, the marker position can be derived from the stray fiel
d components measured by commercial field sensors. Our method was evaluated
by means of a 3D intestinal phantom.
The monitoring procedure yielded the time course of the marker position as
a 3D plot either in real-time or as a time-lapse movie. The spatial resolut
ion, expressed by the mean square deviation, was better than 10 mm and is t
hus sufficiently high to distinguish between adjacent loops of the gut. The
temporal resolution. i.e. the minimum time between two successive measurem
ents, was about 1 s.
The presented method has very moderate technical demands and allows us to m
onitor magnetic markers in real-time. The technique may be useful with resp
ect to Functional examination of the gastrointestinal tract. In pharmaceuti
cal research, our method offers the opportunity for remote drug release at
any position of the gut.