Spatio-Temporal Digital Signal Processing
for Focus Localization from array EEG
Results: The STL Transformation is
capable of isolating events in the time-varying surface potential field taht are
simultaneously sharp in space and in time, which characterizes focal interictal events in
If an event is only sharp in time (such as muscle artifact) or only
sharp in space the STL transformation will not emphasize it.
This figure compares a traditional 16 channel EEG record (top half) with the
instantaneous maximum found over the array of electrodes ("imoa")for all three
of the transformations: SL, TL and STL. It can be observed that only a true
interictal event in the second half of the interval is represented by the STL. Two events
that were sharp in time only (arrows) are represented by the TL, but not by the SL , and
therefore do not appear in the STL imoa.
Method: Spatio-Temporal Laplacian