Respironics Trilogy 02, Technical Information

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P
AGE
4-9
T
RILOGY
S
ERVICE
& T
ECHNICAL
I
NFORMATION
1002735, V
ER
. 05
4.5 S
ENSOR
B
OARD
The sensor board is the main source of pressure and flow feedback for the Trilogy ventilator. It supplies the
system board with real time digital pressure and flow data. This data is processed by the system board and
used to control the blower speed and supply the prescribed pressure and flow support to the patient.
F
IGURE
4-5 S
ENSOR
B
OARD
B
LOCK
D
IAGRAM
The circuitry on the board contains seven sensors, sensor conditioning circuits, ADC (Analog to Digital
Converter), and linear and reference voltage sources. Six of the sensors are on board and one (the dual
element temperature sensor) is located in the air stream and connected to the board through cabling (J1).
Signals that are critical for patient therapy have separate sensors for control functions (machine blower control)
and monitoring functions (alarms and patient parameters). All sensors are powered by the 5VDC regulator
(U7) except dp monitor flow sensor (MT4) which is powered by the 10VDC precision reference (U10). All
sensor outputs are ratio-metric to the power supply.
To System Board
5VDC
Regulator
Divide by 2
2.5V
Reference
ADC
2:1
mux
Control
Flow
Sensor
Control
Pressure
Sensor
Monitor
Pressure
Sensor
dp Monitor
Flow
Sensor
Prox
Pressure
Sensor
Barometric
Pressure
Sensor
Auto Null
Valve
Manifold
Buffer &
Low Pass
Filter
Buffer &
Low Pass
Filter
Buffer &
Low Pass
Filter
Gain & Low
Pass Filter
Buffer &
Low Pass
Filter
Buffer &
Low Pass
Filter
Gain
Valve
Control
Low Pass
Filter
1
1
To All
Sensors
(except dp
Monitor Flow)
Flow Element
Dual Element
Thermistor
Pressure
Port
Atm
Prox Flow
Prox Pressure
Th
er
mi
sto
r
7VDC
Regulator
10VDC
Reference
12VDC
Regulator
To dp
Monitor
Flow
Sensor