Siemens SC 7000 Service Manual page 44

Service Manual
9.7 Non-volatile memory
9.8 Hose detection
9.9 Watchdog Timer
Press
Transducers
HemoMed
Cardiac
Output
Keypad
Figure 2-14 HemoMed Front End
10HemoMed Front End
10.1 Introduction
10.2 Pressure
28
• Neonatal mode switching of pump and overpressure
• Safety logic
A EEPROM stores pneumatic component flow factors. During calibration at
production system test and in the field, a 0.5 liter canister is connected to
the NBP input on the monitor. The monitor automatically measures the
pump and valve flow rates and determines their flow factors for the use in
the flow control algorithm.
An electromagnetic coil located at the hose connector detects the metal in
the hose connector when the connector is present.
A watchdog timer is implemented in the power conversion FPGA to monitor
the safety timer clock input from the main FPGA in case the main FPGA or
its crystal become damaged.
4
Clamp and
Filter
2
Pressure Sense Excitation
Excitation
Linearization
Refer to Figure 2-14. The HemoMed front end section of the monitor's main
board takes invasive blood pressure, and thermal dilution cardiac output
data gathered by the HemoMed Pod from transducers at the patient and
converts them to digital form for transmission through isolators to the
computer section of the main board. The HemoMed front end may also be
used with a single or dual pressure cable instead of using the HemoMed.
The pressure data acquisition front end is designed to operate with resistive
strain gage pressure transducers having an output impedance of less than
3000 Ohms and an input impedance between 3000 and 200 Ohms.
Excitation voltage is applied in pairs. Press 1 and 3 share a driver as well
as Press 2 and 4. The output signals generated from the pressure sensors
are passed through filter and clamp networks which limit and filter RF noise.
The pressure excitations are monitored for fault detection.
Siemens Medical Systems, EM-PCS, Danvers
NOT A CONTROLLED DOCUMENT
SC 7000 and SC 9000XL Patient Monitors
Keypad
Power Monitor
4
Pressure
M
U
X
2
Reference
Temperature
Control
3
Temperature
(Inj. blood, .7R)
7k9kXLTM.c2.CD_ROM.fm/04-99/kaupp
16 Bit
A / D
Converter
Asic
Data Control
Power
Com
Pod
ASK-T898-03-7600