Another group of fall detection systems use floor pressure
and gravity sensors. These systems are very costly and likely to
be inaccurate because of the requirement of using many
sensors to cover all the living places [4]. Moreover, a System
which uses 3D tags and ultrasonic sound receivers around the
rest home room may be smart solution, however this requires
redesign of the environment, and it may fail due to the
reflections of the sound waves by walls