Service manual

CHAPTER 6FUNCTIONAL DESCRIPTION
76 9650-0801-01 Rev. A
Main Processor (MP)
The MP section controls the user interface, connectivity needs, as well as data logging,
printing, and general system control. It consists of the CPU, program memory Flash and
SDRAM, Communication with modules/circuits: USB Client, USB Host, Debug Ports
(JTAG,Serial), Storage memory for 24 hour disclosure data, Internal VGA display and interface
circuit, LED indicators, Key Pad, and Audio circuit. The MP also controls the real-time clock
and interface to the power controller processor, battery and charger.
Patient Processor (PP)
The Patient processor circuitry supports the data acquisition, signal processing and
conditioning, analysis and control algorithms required for the physiological sensors. The PP
also controls the defibrillation and pacing circuitry. It consists of the processor, program
memory Flash and SDRAM as well as interface circuitry to physiological sensor modules/
circuits.
Power Controller (PC)
The Power Controller (PC) micro-controller controls the power sequencing to turn the device
on and off when the power switch is pressed. It also communicates to the battery charger and
battery via a serial SPI bus. Additionally, the PC controls the Status LCD and communicates
battery and charger status to the MP.
ECG 3/5 or 12 Lead Circuitry
Propaq MD supports 3/5 lead and 12 lead ECG acquisition. Analog circuitry provides signal
conditioned data through an A/D converter to the PP. All of the signal processing, lead
derivation, fault detection is performed by the PP. The ECG circuitry utilizes a CPLD for
control of analog circuitry and transmission of data to the PP across an isolation barrier. A
common connector is used to receive 3/5 Lead ECG cables with a 12 Lead ECG extension. The
ECG acquisition inputs are CF defib-proof applied parts. The defib protection resistors reside in
the patient cable. The ECG signals from the external connector on the left side panel are
connected to the monitor board through a flex cable to J28.
Impedance Respiration
Propaq MD provides the circuitry for impedance respiration measurements in 3/5 and 12 lead
configurations. This circuitry provides a low-current 72kHz AC signal across leads I and II of
the ECG cable. The signal is passed through a synchronous demodulator and decoded by the PP
through the ECG CPLD.
Blood Pressure NIBP
The Propaq MD NIBP circuitry resided on module that connects to the Monitor board through
J32. The PP communicates to the NIBP module via a bi-directional, serial bus. The NIBP
module supports both dual lumen and single lumen cuffs. The NIBP pump and valve hoses are
connected to the cuff connector on the left side panel and to the filter on the rear enclosure. The
pump and valve are connected to the NIBP module by short, 2-wire cables.
Invasive Blood Pressure (IBP)
Propaq MD supports up to 3 IBP measurement channels. The IBP circuitry supports AAMI
BP-22 transducers (5uV/V/mmHg). The PP communicates directly to the IBP ADC over an