System Processing Description 89
ECG
Processing
The
measurement
of
the
skin
surfaces
electrocardiogram
is
based
on
the
electrical
signals
on
the
skin
surface,
produced
as
the
heart
muscle
contracts
and
relaxes.
The
signals
are
detected
by
electrodes
placed
on
the
patient
body.
The
information
on
heart
activity
carried
by
these
signals
varies
with
the
placing
of
the
electrodes.
The
technique
used
in
ECG
senses
the
varying
potential
difference
between
two
points
at
the
skin
surface
which
respond
to
the
chemical
actions
of
the
muscular
activity
of
the
heart.
Three
electrodes
are
attached
to
the
patient’s
right
arm
(RA),
left
arm
(LA)
and
left
leg
(LL).
The
varying
potentials
at
these
locations
are
cable
‐
connected
to
the
ECG
circuit
inputs
where
they
are
conditioned,
and
the
difference
of
potential
between
two
selected
leads
is
digitized
before
transmitting
through
opto
‐
isolators
to
the
processor.
The
processor
‐
installed
algorithms
operate
on
the
signals
to
develop
drivers
for
the
graphic
display
and
to
compute
the
heart
rate
in
beats
per
minute
(bpm).
In
addition
to
the
acquisition
of
the
QRS
waveform
complex,
the
ECG
input
and
subsequent
signal
processing
computing
circuitry
perform
a
number
of
other
functions:
z
They
detect
a
lead
‐
off
condition
if
one
of
the
electrode
connections
is
disrupted.
z
They
detect
the
presence
of
pacemaker
signals
within
the
QRS
waveform
complex
of
the
ECG.
NIBP
Processing
Overview
The
oscillometric
technique
does
not
use
Korotkoff
sounds
to
determine
blood
pressure.
The
oscillometric
technique
monitors
the
changes
in
cuff
pressure
caused
by
the
flow
of
blood
through
the
artery.
The
monitor
inflates
the
cuff
to
a
pressure
that
occludes
the
artery.
Even
when
the
artery
is
occluded,
the
pumping
of
the
heart
against
the
artery
can
cause
small
pressure
pulses
in
the
cuff
baseline
pressure.
The
monitor
lowers
cuff
pressure
at
a
controlled
rate.
As
the
cuff
pressure
goes
down,
blood
starts
to
flow
through
the
artery.
The
increasing
blood
flow
causes
the
amplitude
of
the
pressure
pulses
in
the
cuff
to
increase.
These
pressure
pulses
continue
to
increase
in
amplitude
with
decreasing
cuff
pressure
until
they
reach
a
maximum
amplitude
at
which
point
they
begin
to
decrease
with
decreasing
cuff
pressure.
The
cuff
pressure
at
which
the
pulse
amplitude
is
the
greatest
is
known
as
Mean
Arterial
Pressure
(MAP).
The
manner
in
which
the
pulse
amplitudes
vary
is
often
referred
to
as
the
pulse
envelope.
The
envelope
is
an
imaginary
line
that
connects
the
peak
of
each
pressure
pulse
and
forms
an
outline.
The
shape
of
the
envelope
is
observed
by
the
monitor
using
a
variety
of
techniques
to
determine
the
diastolic
and
systolic
blood
pressure.
Содержание YM6000
Страница 6: ...iv Contents YM6000 Service Manual This page is intentionally left blank...
Страница 14: ...8 Introduction YM6000 Service Manual This page is intentionally left blank...
Страница 50: ...44 Service Menu and Factory Default Settings YM6000 Service Manual This page is intentionally left blank...
Страница 66: ...60 Troubleshooting YM6000 Service Manual This page is intentionally left blank...
Страница 82: ...76 Disassembly Guide YM6000 Service Manual This page is intentionally left blank...
