<s>
Human	B-General_Concept
sensing	I-General_Concept
(	O
also	O
called	O
human	B-General_Concept
detection	I-General_Concept
or	O
human	B-Algorithm
presence	I-Algorithm
detection	I-Algorithm
)	O
encompasses	O
a	O
range	O
of	O
technologies	O
for	O
detecting	O
the	O
presence	O
of	O
a	O
human	O
body	O
in	O
an	O
area	O
of	O
space	O
,	O
typically	O
without	O
the	O
intentional	O
participation	O
of	O
the	O
detected	O
person	O
.	O
</s>
<s>
Modern	O
technologies	O
proposed	O
or	O
deployed	O
for	O
human	B-General_Concept
sensing	I-General_Concept
include	O
:	O
</s>
<s>
Detection	O
of	O
the	O
mobile	O
phone	O
,	O
computer	O
,	O
Bluetooth	B-Protocol
,	O
or	O
Wi-Fi	O
signals	O
of	O
a	O
device	O
assumed	O
to	O
be	O
in	O
the	O
possession	O
of	O
a	O
person	O
.	O
</s>
<s>
In	O
September	O
2013	O
,	O
the	O
United	O
States	O
Department	O
of	O
Homeland	O
Security	O
's	O
Science	O
and	O
Technology	O
Directorate	O
demonstrated	O
a	O
prototype	O
of	O
the	O
FINDER	O
radar	B-Application
technology	O
device	O
,	O
which	O
it	O
developed	O
in	O
conjunction	O
with	O
NASA	O
's	O
Jet	O
Propulsion	O
Laboratory	O
.	O
</s>
<s>
FINDER	O
uses	O
microwave	B-Application
radar	I-Application
to	O
detect	O
the	O
unique	O
signature	O
of	O
a	O
human	O
's	O
breathing	O
pattern	O
and	O
heartbeat	O
,	O
through	O
20	O
feet	O
of	O
solid	O
concrete	O
,	O
30	O
feet	O
of	O
a	O
crushed	O
mixture	O
of	O
concrete	O
and	O
rebar	O
,	O
and	O
100	O
feet	O
of	O
open	O
space	O
.	O
</s>
<s>
In	O
September	O
2014	O
,	O
the	O
DHS	O
promoted	O
the	O
technology	O
to	O
SWAT	B-Application
teams	I-Application
at	O
the	O
Urban	O
Shield	O
trade	O
show	O
.	O
</s>
