Physio Control LIFEPAK 9 - Functional Description

LIFEPAK 9 defibrillator/monitor
Functional The overall function of the LIFEPAK 9 defibrillator/monitor is shown in
Descri ption Figure 1-2. The defibrillator/monitor includes six mechanical assemblies
(Keypad, Rear Panel Membrane Switch, Strip Chart Recorder, Transfer
Relay, Paddles, and Battery Pack) and five Printed Circuit Board (PCB)
assemblies (Power Supply, Power Conversion, Interconnect, Main, and
Display).
The Keypad and Rear Panel Membrane Switch Assemblies receive operator
input. The Strip Chart Recorder Assembly provides printed output. The
Transfer Relay and Paddle Assemblies help deliver defibrillator pulses. The
Battery Pack provides temporary backup power.
The Power Supply PCB functions over the full range of input voltages from
90Vac to 270Vac at 50Hz or 60Hz without input line voltage selection. The
Power Supply PCB converts the ac line power to the nominal +18.8Vdc
supplied to the Power Conversion PCB.
The Power Conversion PCB performs a variety of power-handling functions:
power on/off switching, generation of additional power supply voltages,
defibrillation charging, and stored energy transfer. A test load circuit is also
present on the Power Conversion PCB.
The Interconnect PCB provides the electrical connection between the Main
PCB and the Power Conversion PCB. It also contains circuitry to produce
the audible tones and to drive the front panel LEDs.
The Main PCB has three major sections of circuitry: the Preamp, the System
Controller, and the Display/Recorder Interface. The Preamp receives input
from both the 3-lead patient cable and QUIK-LOOK paddles inputs. The
System Controller directs the overall operation of the other circuits. QRS
detection, rate calculation and alarms, and synchronous cardioversion are all
implemented in the System Controller software. The current state of the
System microprocessor and the ECG data are transmitted from the System
microprocessor to the Display/Recorder microprocessor, allowing the
Display/Recorder microprocessor to select and format the appropriate CRT
messages and recorder annotations.
The Display PCB/CRT Assembly contains a Monitor PCB that drives the
5-inch diagonal Cathode Ray Tube (CRT). It uses electromagnetic beam
deflection and incorporates vertical and horizontal deflection circuitry to
produce a raster scan.
1-6 All Rights Reserved © August 1993 Physio—Control