Wrapper of readEdfHeader, but added
some information
Details
The added names are: isAnnot2, sampleRate2, and
unit2. To avoid conflict with other names, there is a "2" appended
to each names. isAnnot2 indicates whether each channel is annotation
channel or recorded signals. sampleRate2 is a vector of sample rates
for each channels. unit2 is physical unit of recorded signals.
For 'iEEG' data, this is electric potential unit, and choices are 'V'
for volt, 'mV' for millivolt, and 'uV' for micro-volt.
For more details, see https://www.edfplus.info/specs/edftexts.html