The thresholds:
A threshold is a value used to determine whether a movement is of one type or another.
A good threshold is a key part to making a fall detector. A bad threshold may give false positives
or false negatives. If a fall threshold were to be too high, a fall would not be sensed (see figure
4). On the other hand, if a too low threshold is used, this would would make the fall detector
generate false alarms (see figure 5). The right threshold is one that would allow a fall to be
detected, but not to set off an alarm when not needed. I selected the thresholds by
experimenting, while performing different activities. All in all, these experiments lasted for more
than ten hours.