Once the signals are filtered and delineated,
template design operates on isolated heartbeats rather than the signal in total.
Intuitive rules are defined to guide this process based on the physiological properties of a heart beat. More specific,
every pulse is segmented into two parts, one that is prone
to heart rate changes and a more stable one. According to
[18],the T wave is vulnerable to heart rate changes, by
coming closer to the QRS complex at rapid rates. However,
this contraction property does not apply to the P wave or the
QRS complex. Therefore, every segment that is signified by a
P wave onset, and up to the respective offset, is resampled to 120ms (approximate healthy duration under rest [18]), while
the remainder of the pulse is retained. An average among
a number of such processed heart beats for every subject
is considered a template, and is stored in the gallery set.
During testing, an input heart beat is matched against the
stored templates using the correlation coefficient as a similarity
measure. More details pertaining to this method can be found
in [12].