Facilitating the annotation of seizure events through an extensible visualization tool

An electroencephalogram (EEG) is a multi-channel signal which describes the electrical activity in the brain via voltages measured in a variety of locations on the scalp. EEG recordings can be interpreted using montages, which redefine channels as the difference of channel voltages. EEG recordings are most commonly stored as raw signals in the European Data Format (EDF). Existing EEG visualization tools, such as EDF Browser [1] and EEGLab [2], do not allow users to annotate directly over their signal displays. Furthermore, it is not possible to easily add new visualizations to these tools. Our tool displays annotations in a time-aligned format, and allows the direct creation and manipulation of these annotations. We provide an extensible framework that allows for the creation of new visualizations or analytics based on user needs. In addition to the conventional multi-waveform viewing capability to which neurologists are accustomed, we provide a spectrogram and/or energy visualizations. These visualizations are becoming increasingly popular with clinicians as an efficient way to review continuous EEGs [3] (cEEG). In this presentation, we will introduce a software tool that facilitates annotation of EEG signals.