<s>
A	O
kymograph	B-Algorithm
(	O
from	O
Greek	O
κῦμα	O
,	O
swell	O
or	O
wave	O
+	O
γραφή	O
,	O
writing	O
;	O
also	O
called	O
a	O
kymographion	O
)	O
is	O
an	O
analog	O
device	O
that	O
draws	O
a	O
graphical	O
representation	O
of	O
spatial	O
position	O
over	O
time	O
in	O
which	O
a	O
spatial	O
axis	O
represents	O
time	O
.	O
</s>
<s>
It	O
basically	O
consists	O
of	O
a	O
revolving	O
drum	O
wrapped	O
with	O
a	O
sheet	O
of	O
paper	O
on	O
which	O
a	O
stylus	B-Operating_System
moves	O
back	O
and	O
forth	O
recording	O
perceived	O
changes	O
of	O
phenomena	O
such	O
as	O
motion	O
or	O
pressure	O
.	O
</s>
<s>
The	O
kymograph	B-Algorithm
was	O
initially	O
a	O
mechanical	O
and	O
hydraulic	O
device	O
,	O
invented	O
by	O
German	O
physiologist	O
Carl	O
Ludwig	O
in	O
the	O
1840s	O
,	O
and	O
found	O
its	O
first	O
use	O
as	O
a	O
means	O
to	O
monitor	O
blood	O
pressure	O
.	O
</s>
<s>
The	O
blood	O
pressure	O
was	O
conveyed	O
by	O
hydraulics	O
and	O
levers	O
to	O
move	O
a	O
stylus	B-Operating_System
that	O
scratched	O
a	O
white	O
trace	O
into	O
soot-covered	O
paper	O
on	O
the	O
revolving	O
drum	O
.	O
</s>
<s>
Time	O
is	O
represented	O
by	O
the	O
drum	O
's	O
rotation	O
rate	O
,	O
and	O
was	O
recorded	O
by	O
a	O
further	O
stylus	B-Operating_System
driven	O
by	O
a	O
clock	O
or	O
tuning	O
fork	O
.	O
</s>
<s>
The	O
kymograph	B-Algorithm
almost	O
immediately	O
became	O
the	O
central	O
instrument	O
in	O
physiology	O
and	O
physiology	O
education	O
.	O
</s>
<s>
Kymographs	B-Algorithm
were	O
also	O
used	O
outside	O
medical	O
science	O
to	O
measure	O
atmospheric	O
pressure	O
,	O
tuning	O
fork	O
vibrations	O
,	O
the	O
functioning	O
of	O
steam	O
engines	O
,	O
animal	O
habits	O
and	O
the	O
movement	O
of	O
molecules	O
in	O
cells	O
.	O
</s>
<s>
The	O
kymograph	B-Algorithm
is	O
generally	O
used	O
to	O
study	O
the	O
effects	O
of	O
xenobiotics	O
on	O
tissue	O
preparations	O
.	O
</s>
