GE Corometrics 250cx Series, Service Manual, Page: 47 / 252

Revision C 250cx Series Maternal/Fetal Monitor 2-19
2036947-001
Equipment Overview: Theory of Operation
Vide
o Fle
x
data
c
able
Main Board/NIBP
The m
ain board
houses
the ce
ntral
process
or and is t
he
focal
point for
all data in t
he
120. The
boa
rd is responsi
ble
for th
e fo
llowing:
•
Receives proce
ssed
FECG
, Ultrasound, UA,
and
MECG data fro
m
th
e DSP board
•
Form
ats DSP
data for
display
•
Passes
display
data to t
he
DSP board display
FPGA
which i
n turns
dri
ves t
he LC
D
panel.
•
Writes the processed
data to t
he
recorder
board
•
Receives
front panel keypa
d/t
rim
knob
data from
the UI
board
•
Com
m
uni
cat
es pa
ram
eter dat
a to the
rea
r
pa
nel
comm
. Ports
•
Passes param
eter telem
etry da
ta to the
DSP
board
fr
o pr
ocessi
ng
.
•
Inputs key
pad
data from
rear
panel c
om
m
. Board
and sends it to
the recorder
board
•
Exec
utes dia
gnostics
o
Reports its own m
ain failures
o
Reports UI key
pad
and DS
P f
ailures
o
Reco
rd
er test pattern
an
d d
isplay test
pattern
o
Audio test patt
ern
•
Provides NIBP processing subsy
stem
&
co
mm
unicat
es to the external Pneumati
cs
PWA.
DSP/Display Interface Board
The DSP/Display interface board form
s
the
bridge between the fr
ont–e
nd parameters and
the main board central processor. It also has the function of display
interface. It interf
aces
the Main boa
rd to the LCD
panel by
providi
ng a
dual port m
emor
y to t
he m
ain
board and a graphics engine driving t
he
LCD
panel. The bo
ard is responsible for the
following:
•
Interfaces to front-end m
otherboard
which holds the param
eter boards
•
DSP Processing of FECG,
MECG,
UA, and Dual Ultrasound d
ata thus
converting an
alog data to h
eart rates
and pressure values.
•
Sending
of processed data to m
ain
board
•
Pass through of MSpO2 O
E
M
m
odule serial communication lines to
the main board (no
processing done
by
DSP)
•
Provides status of patient
cables
plugged in to
m
onitor to the
m
ain
board
•
Drives the LCD display panel by generating the video graphics through the FPGA chip and sendin
g data to
the decoder b
oard which th
en
connects to the LCD displa
y
•
Interfaces the video to the
main board
processor through a dual port m
emory
•
Pass through
of front
panel serial
co
mm
lines t
o the main board
•
Generates VGA video output to rear panel
Digitally Processed
Anal
og Pa
ram
eter
Data
Un-Proces
sed Anal
og
Param
eter Data
From
tele
m
etr
y
Gra
phics Data
for display
Pass thr
ough
M
S
pO
2 &
F
S
pO2
serial data & R
eset
Recorder Board
Interfaces main board serial data to recorder printhead Provides regulated power to printhead Provides sensor data from recorder door, paper out & paper m
isload to m
ain board
Pass thr
ough
UI
Keypa
d se
rial data
Front-end
Motherboard
Connects front- end bds together distributing isolated power and un-isolated power. Passes th
rou
gh
all analog signals to the DSP board for processing.
FECG/UA Board
Converts fetal ECG to analog signal for processing Converts pressure signal to analog for D
S
P signal
processing
MECG Board
Converts 3 lead maternal ECG signals to analog signal for DSP processi
ng
Dual Ultrasound Board
Provides doppler shift analog signals to DSP board
SpO2 Carrier Board
Carries MspO2 m
odule
connecting to FE m
thbd
MspO2 Module
Provi
des serial MspO2 data t
o
main
b
oard
Isolated Power Supply
Provides isolated power to all front-end boards excluding US board
All
Analog Signals
Telem
etry
US data
UI Keypad
Passes all button closures and trim
knob
data to
main bd via DSP board. Provides the
chart light & key
backlight
function
under m
ain board control
Interfaces serially t
o the m
ain bd
Serial key
pad
data cab
le
Comm Board
Interfaces e
xt
keypa
d to m
ain
boa
rd
Interfaces e
xt t
elem
etry analog si
gnals t
o m
ain bd
Interfaces le
ga
cy Spectra
anal
og cent
ral by
sending
.
Telem
etry
analog si
gnals
Keypa
d
signals
Anal
og
HR
out
put
s
Anal
og HR
signal
with
M
od
e In
fo
Anal
og HR
signal
with
M
od
e In
fo
Lead selection,
Pacer e
na
ble, t
est
sig
na
l en
ab
le
Serial d
igital Mp
O2
/
data
MSpO
2 Resets
Serial d
igital Mp
O2
data
FECG + MECG Front pan
el
Connector
FECG
UA ca
bles (2)
MECG
cable
Anal
og HR
signal
with
M
od
e In
fo
FECG & UA signals
Power for
MspO
2/Fs
pO
2,
FECG, and M
E
CG
boa
rd
s
Sy
stem
+20
vo
lts
for s
w
itchin
g
l
Serial di
gital
Mp
O2
/FSp
o2
data MSp
O
2/
FSpO2
Resets
UI Volume
Keypad
Holds volum
e
& alar
m
cancel buttons
US
1
Connector
US
2
Connecto
r
M
spO
2 FP
Connector Bd
UA Front Panel Connector
UA cable
US
1 ca
ble
US
2 ca
ble
MS
pO2 ca
ble
Isolated
Isolated
Denotes Patient Isolated Sections
Video Decoder
Board
Translates 4 bit color to 18 bit color for LCD
LCD
Panel
320 X 240
Inverter
Module
Vol
um
e
data cab
le
DSP/
Decode
r
Vide
o ca
ble
DSP
I
nve
rter
Power cable
LCD In
verte
r
cable
(pa
rt of LC
D)
Recorder Seria
l
data/status
Cable
System Po
w
er
Supply
+5, +12, +15, -15
To Main
Boar
d
To Rec
order
Boar
d
Power Ca
bles
Power Ca
ble
from
system
powe
r
supply
Power Ca
ble
from
system
powe
r
supply
Pneumatics
Board
Contains
pum
p, valves
and filte
r
Denotes Plug-in connections
Block Diagram Description
Isolated
Isolated
Isolated
Isolated
Isolated
Partially Isolated
Denotes cab
les
Isolated
VGA Output
Standard V
G
A
output through 15 pin HD conn
N
ew VGA
Vide
o ca
ble
to rea
r
panel
New or Changed for Cheet
ah
Temp.
Module
External
Tem
perature
Module