<s>
General	B-Operating_System
Motors	I-Operating_System
Research	I-Operating_System
Laboratories	I-Operating_System
are	O
the	O
part	O
of	O
General	O
Motors	O
responsible	O
for	O
creation	O
of	O
the	O
first	O
known	O
operating	B-General_Concept
system	I-General_Concept
(	O
GM-NAA	B-Application
I/O	I-Application
)	O
in	O
1955	O
and	O
contributed	O
to	O
the	O
first	O
mechanical	O
heart	O
,	O
the	O
Dodrill-GMR	O
,	O
successfully	O
used	O
while	O
performing	O
open	O
heart	O
surgery	O
.	O
</s>
